


A Mermaid's Home

by thorsten_is_in_the_hood



Category: Shingeki no Kyojin | Attack on Titan
Genre: Alternate Universe - Merpeople, Alternate Universe - Modern Setting, Based on a drawing, Character's Name Spelled as Hanji, It's cute with a hint of angst here and there, Language Barrier, M/M, Scientist Hange Zoë, Titan Eren Yeager, Titan Shifting, ex-military Levi, merman eren
Language: English
Status: Completed
Published: 2017-08-06
Updated: 2017-09-14
Packaged: 2018-12-11 12:57:01
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 21
Words: 26,782
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11714856
Author URL: https://archiveofourown.org/users/thorsten_is_in_the_hood/pseuds/thorsten_is_in_the_hood
Summary: Hanji and Levi were on a search to find and study tropical mermaids.Instead, they find something better- Eren, the type of mermaid that was thought to be nothing more than a myth.Based on the lovely drawing of Kelbremdusk: http://kelbremdusk.tumblr.com/post/159656303599





	1. I did not expect that

**Author's Note:**

> ♥ Big thanks to my lovely beta Claudia, she's the best! ♥
> 
> So, the first chapter is a bit brutal, but it will have it's cute moments, I promise!!  
> Also, I don't give out any specific trigger warnings, if you're a fan of SnK/AoT you know what you're in for. The only extra is the mention of vomiting and sexual content in there. But really, it's not as dark as the anime/manga :)

"Why do I even have to come along, shitty glasses?" Levi asked as he fought himself through the deepest jungle.

"Oh come on, it'll be fun! Just you, me and a sea full of mermaids to study!" Hanji exclaimed in a way too excited tone for the raven's liking. "I mean, we get along pretty good with the river mermaids, but there are probably so many other kinds! The tropicals barely interact with humans, so a documentary will be like, the coolest thing ever!!!"

"Just. Please. Shut the fuck up." Levi sighed. "You just needed some idiot to carry all your damn shit."

Hanji began to laugh at that. "It's not _completely_ like that, Levi!"

"So you admit it..." Levi grumbled.

"Levi, stop whining, it's great! I know that you needed to go outside anyways, you were practically suffocating in New York, filling in papers for Erwin!"

Shortly after, they reached the end of the jungle and were looking at the ocean. Hanji began building their little camp with a happy smile. "I can't wait to see them, Levi! Did you know, the river mermaids all have these green or sometimes blue colors, but tropical mermaids are really colorful! They can be brightly yellow, red, ..."

Levi tuned the talking of his friend out and looked around for food, silently walking away. When he returned with a bag of tropical fruits and crabs, he saw Hanji already talking to a mermaid.

"You're about the size of river mermaids, that's very interesting given the fact that- oh, hey Levi! This is Frieda, she said she'll lead us a bit through their world! Isn't that just awesome?!"

The mermaid smiled and bowed her head a little. "Nice to meet you, Levi. Anyways, if you want to film our group that's okay. You just have to follow our pace, we're nomads."

Hanji's eyes lit up and went to grab her hands. "Tell me everything. Levi, go get the camera."

Levi rolled his eyes but reluctantly dropped his bag and began to film.

"So... Are all tropical mermaid groups nomads?"

Frieda hummed a second in thought. "Only the ones that live in the ocean, other groups that live in seas or bays don't, because it's not deep enough to be dangerous for them."

"Dangerous?" Levi asked, getting a little interested.

Frieda nodded. "Yeah. In the deeper waters... there are horrible monsters that eat mermaids, probably humans as well."

Hanji squeezed the hands in their own tighter. "What do you mean, monsters? What kind of creatures eat mermaids, I've never heard of anything like that before!"

The mermaid looked away. "I never saw them either, but others say that they almost look like their own kind of... deep sea mermaid? But they're huge. Insanely huge."

Hanji began trembling with excitement. "Levi. This journey changed, we'll try to find a deep sea mermaid!"

"Oh fuck no." Levi immediately answered. "If it's like she described, then I don't want to end up as their dinner, shitty glasses."

Frieda shook her head. "He's right, searching for them would be straight suicide."

Hanji pouted, but let the subject go, instead of asking all kinds of things about tropical mermaids again.

At one point, they took a break to eat and pack up their things again to catch up with Frieda's group. Most of them welcomed them and were just as curious as they were.

-~-

The group was sleeping near the shore, partly buried under the sand to hide their colors. Hanji and Levi set up their tent a little further from the beach to avoid it getting wet from the tides. A few mermaids stayed awake though, watching over the sleeping mermaids.

It was already sunrise when Levi was ripped out of his sleep, hearing shouts. He quickly shook Hanji awake as well and climbed out of the tent.

"Levi! Hanji! RUN!" Frieda screamed.

The two humans took in the scene in pure shock and horror. Two giant mermaids were there, one devouring the group of tropical mermaids. They were both big enough to take them into their mouth in one piece and the one eating barely chewed before swallowing.

"HOLY SHIT, THEY'RE REALLY HUGE!" Hanji screamed. "AT LEAST 15 METERS, IF NOT 20!"

"Hanji. For the love of God. Shut. The fuck. Up." Levi whispered through gritted teeth.

The eating one shot forwards with a strong flip of his tail and swallowed Frieda as well. Levi froze in place and stared at the creature as it ate her. He saw out of the corner of his eyes that Hanji was filming, which made his stomach flip. After a minute, the whole group was gone.

"If they see us, we're fucked." was what left Levi's mouth through the chaos of his thoughts.

The other deep sea mermaid pushed itself in front of the other and let out a low growl. The two had a short staring match before the first left silently.

The second one turned back around and looked directly at the humans.

"U-Uhm... Hi there." Hanji said nervously, never lowering the camera.

The giant lowered itself to the ground to take a closer look at them. It's immense, brown tail with little, glowing green dots, curled in behind it. And just like the dots were two glowing, green eyes staring at them.

"Hanji, run as fast as you can. I'll try to distract this thing for a while."

The mermaid growled again and lowered it‘s head even further, brown hair falling into its face.

"Are you _crazy?!_ I won't leave you behind!" Hanji said and against every instinct they had, stepped closer.

Levi wanted to scream and pull Hanji back before the deep sea mermaid could devour them, but to his surprise, did the giant nothing, only silently staring.

"I... I did _not_ expect that."

The huge mouth opened to let out a deep breath before closing again, showing how it didn't have lips, only sharp teeth that nearly split its face in half.

Hanji stepped even closer, panting in their excitement. "Levi... We're the first humans to see a deep sea mermaid... this is incredible!"

"Yeah, until it get's hungry again and eats us. Can't wait for that." Levi huffed.

"If you're scared, then let's set up the camera here and put the tent further into the jungle" Hanji suggested.

"Of fucking course I'm scared! I can't believe that you aren't, Hanji!" With that, Levi turned around and stormed off to calm down and to search for food so they wouldn't have to use their rations.

-~-

"Look at that. You're still alive." Levi said as he returned a few hours later.

Hanji's eyes lit up when looking at Levi. "This mermaid is so cool! Earlier, it threw fish into the air with it's tail and caught them in it's mouth! Its mouth isn't shaped to be able to speak, so I wonder how it communicates, is it all just growls? And why does it eat mermaids, but not us? And most importantly-"

Levi groaned and ran his hands over his face. Everything was insane, how did he end up in this situation, somewhat calmly talking with Hanji in the presence of a giant man-eating carnivore. He raised an eyebrow when he heard it huff small breaths.

"Is it... laughing at us? I think it's laughing at us."

"Maybe it _does_ understand some things!" Hanji squealed excitedly and began to talk with the giant about anything that came to their mind.

"This is why I hate going anywhere with you..."


	2. Patience

Two days later, they were still on that beach, watching the deep sea mermaid. It disappeared over the night and ate little fish with his tail flips that got the scientist extremely excited every time, and the creature seemed to enjoy the attention.

Hanji still tried to talk with the giant, even though they said it themselves; that it doesn't understand them, and isn't even capable of speaking with the way its mouth was shaped.

"I have an idea! Hold the camera, Levi." Hanji suddenly shoved the camera in Levi's hands before closing the distance and carefully touching the mermaid's face.

"Hanji, don't forget, they fucking _ate_ a group of mermaids."

Hanji smiled while beginning to pet it. "No, actually, only the other one ate them. This one saved us with pushing itself in between and telling the other to fuck off. At least that's what I think it said."

"Maybe it's not hungry right now and wants to keep us alive until dinner time."

Hanji laughed at that, causing the creature to squint its eyes. "He only eats little fish instead of me, so I have a feeling that he's nice. Do you think he has a name?"

Levi shook his head. "I can't believe you, shitty glasses."

"HEY!" Hanji screamed out of nothing. The mermaid flinched and growled in confusion. "Do you have a name?"

The answer was exactly was Levi thought it would be. A growl. Followed by tilting its head.

"I think it doesn't speak english," Levi said and sat down in the sand. He saw the mermaid slowly reaching for him with its big, clawed hand. He stayed completely still, blinking in disbelief when he felt the creature ruffling his hair with a finger.

"It's so cuuuute!" Hanji squealed and rubbed her cheek against the mermaid's. It laughed in return and pushed back a little.

Levi turned the camera to film his face. "There it is, folks. Here you can see two insane humans, chilling with a man-eating monster."

The mermaid quickly began to stare at Levi and roared. Loud.

Hanji pulled back for a moment before touching its face again. "What's wrong? Don't you like being called a monster?" Another roar confirmed her guess.

"I wonder why... Hey, Levi?"

"What?"

"Can we keep him?" Hanji asked with big eyes, causing Levi to facepalm.

"Are you fucking serious?"

"Yeah! If we could teach him our language, then he could tell us so many things about deep sea mermaids!" Hanji said and then turned to the mermaid, grinning wide.

"You said it couldn't talk, idiot. Also, how do you even know it's a male?" Levi raised an eyebrow.

"Uh... good question-" Hanji got interrupted when suddenly the mermaid collapsed and began steaming.

"What the fuck?!"

"Oh my gosh, Levi! Do you realize what's happening?!"

Levi frowned. "No, this is all too fucked up."

Hanji grinned and put a finger up, beginning her lecture. "A long time ago, there were man-eating giants, called titans, that roamed Earth. Today there aren't any Titans on earth anymore, though. There are some tales that say that some humans were able to transform into titans, or that Titans could turn into humans. But, no one knows what's true or not about Titan stories, since only a few people survived being near them that time. But this... It's like an underwater titan! Maybe even an underwater titan-shifter!"

Levi grabbed his head and sighed. "I think I heard something about Titans as a kid, but it wasn't more than a story."

At the neck, a smaller mermaid emerged from the steaming body and let itself fall into the water.

A second later, a head appeared above the surface that swam closer.

"Okay, that's it. I'm done. So now out of that big ugly monster comes a guy like this?? Fuck this shit!" Levi said with a groan and saw the mermaid giving him a look that could kill.

"Levi, you said it again; the m-word." Hanji chuckled before kneeling next to the shore. "Hey, we never got to introduce ourselves!" They point to themselves, saying "Hanji" and then at the raven "Levi".

The mermaid looked confused for a second before he hummed in understanding and then pointed to himself. "Eren."

"Say, Eren. Do you speak english?"

Eren only tilted his head in confusion.

"I really wanted to learn about your species..." Hanji whined, causing Eren to support himself on the sand shore and look at the scientist closer.

"You said you would teach him, so do it and quit whining." Levi sighed and pulled out his lunch of fruits and fish to eat.

"Oh yeah! I already have a brilliant idea! Keep him company, I'll be right back." With that, Hanji stood up and ran to their tent.

"Oi, brat. Don't look after Hanji like that, it's weird."

Eren stretched out his hand again, but this time not reaching Levi. The raven sighed and got closer, offering a bit of his fish. The mermaid happily took it into his mouth and swallowed the piece whole.

"Levi!" Eren said smiling and gently patted the shorter man on the leg.

"You're looking more like a puppy than a dangerous mon- uh, whatever. I mean look at you, you can't call that scary or anything..."

Eren laughed, sat down on the sand and pointed at Levi and Hanji, who was running back to the shore. Then he opened and closed his mouth like he was speaking and opened his arms wide.

"I'm not talking that much, only shitty glasses can't shut her mouth."

"Guys, I'm back! I got pen and paper so we can start teaching him with drawings!" Hanji said and sat down next to Levi, immediately beginning to draw a smiling and a sad face. "Good. Bad. Yes. No." they explained when showing the drawing and then drew situations, calling them good or bad, as well as yes or no.

"Hanji?" Eren asked smiling and began to reach for the pen and paper himself.

"Of course, Eren."

Eren began to draw Levi and next to him an earth titan. He dragged the pen across from Levi to the Titan.

Levi shook his head. "No. I can't turn into a titan."

"Hanji?"

"No. I can't either." Hanji answered and drew an x over the Titan, but adding humans to Eren's picture. "No Titans." She showed him a single finger and then to her. "Only. Humans."

Eren thought for a second. "No titans?"

Levi nodded. "Yes."

Eren smiled at that. "Good." He angrily pointed at the titan "Monster." then at the ocean "Monster." and afterward at himself. "No monster."

"Why?" Hanji asked and gestured for easier understanding. "Why you no monster?"

Eren picked up the pen again and drew a scene where deep sea mermaids and Titans ate mermaids and humans. Next, to it, he drew himself in his bigger form that only ate little fish. "No monster." He repeated.

Levi smiled a little at that and ruffled Eren's hair like the mermaid had ruffled his. Eren leaned into the touch and hummed happily.

In the meantime, Hanji drew a human at various times of life and then turned to Eren. "Eren, how old are you?"

Eren shook his head and pointed far past the old man, then drew his finger over the cycle, quietly mumbling. Hanji counted until he stopped. "36 lifespans? People around here get around 80, so..." Hanji paused to calculate. "You're over 2500 years old?!"

Levi stopped and looked at the mermaid. "And here I thought I was the oldest..."


	3. History lesson

"2500 years... back then the titans supposed to roamed earth... Eren, do you know how Titans began to disappear?" Hanji asked and pointed to a drawing they made.

Eren looked uncomfortable in an instant and nodded. He grabbed the paper and pen and began to draw little men attacking titans from above with swords. Next to it, he drew two people, a man and a woman in uniforms.

"Humans killed them? Amazing, I would've never thought that! And so detailed... Eren, did you know these two?" Hanji asked, brushing her fingers over the two figures.

Eren seemed to be in thought for a second before pointing at them one by one. "Armin. Mikasa."

"Your friends?"

The mermaid looked at Hanji before smiling a little. "...friends? Levi, Hanji, friends?"

Hanji nodded and pulled Levi into a side hug. "Yeah, we're friends!"

"Armin, Mikasa, Eren friends." Eren shyly looked away and blushed a little. "Levi, Hanji, Eren Friends?"

Hanji actually teared up slightly and pulled Eren into the hug as well. The mermaid jumped at that and gasped.

"This is so damn cheesy, let go dammit." Levi growled and pushed himself out. "But, yes, Eren. We're friends you brat."

"Don't call him a brat, Levi! He may look cute but he's still older!" Hanji laughed.

-~-

"You like Eren, right?" Hanji asked with a grin when they were laying in their tent that evening.

"What're you talking about, shitty glasses?"

"Oh don't even try to hide it. I know you, Levi. The way you look at our little mermaid is the same you had when you first fell in love back then in high school!" they chuckled.

Levi sighed. "I can't do anything against his damn pretty face! I don't even know him, I mean he doesn't even speak our language!"

"...yet. He doesn't speak english yet."

"Whatever. Next thing, how the fuck would I ever fuck him? And what when he's fucking huge again?"

"Now you're just making excuses to not like him. Let's take tomorrow to turn off the camera and just ask things about him."

-~-

"EEREEEEN!" Hanji shouted out to the ocean the next morning. A minute later did Eren appear and swam to the beach. "Hanji! Levi!" he said and waved before blinking. "Äh?" he asked and pointed behind them where normally the camera was.

"Oh, no filming today. We just want to ask you things!"

"Hanji..." Eren sighed and made a gesture to say 'you're talking too much'.

"Ah, sorry." the scientist smiled and reached for the drawing utensils. Hanji drew a picture of Eren, holding another mermaid's hand. "Do you have a mate?"

Eren blushed a little and drew an x over the mate like Hanji did with the Titan the other day. "I... no... have a mate?"

"Yes! This is mate." Hanji explained and pointed at the drawing.

Eren thought for a second before crawling further along the sand beach and grabbed Hanji's hand. "I... have Hanji?" Then he grabbed his tail. "I have Eren?"

"Yes, not bad..." Levi said pleased and sat closer to the water to pick up a shell. "I have a shell."

"Ashell?" Eren asked and took the shell. Levi shook his head.

"Shell." He pointed at it saying "A shell." then he picked up another and put it into Eren's hand. "Two shells."

Eren frowned at his hand, clearly upset about the difficulties of the english language.

Hanji chuckled and put her hand on Eren's shoulder and smiled. "Alright then, I'll go get some food!" With that, Hanji got up and dashed towards the jungle.

"Tch, shitty glasses." Levi huffed. "So, Eren. You have other friends?"

Eren turned around to look out to the ocean. "No good friends." There was a sad look on Eren's face.

"Oh... sorry." Levi answered and ruffled the mermaid's hair. Eren turned back around and gave Levi a soft smile. "Levi, Hanji, friends. Good friends."

The raven returned the smile. "You're really a cute brat."

Eren reached for the notebook and drew himself with Levi sitting on his head, sunbathing. "Levi?"

The raven thought about it for a moment, but he knew he couldn't resist with Eren staring at him, hope in his eyes."Uh... as long as you don't drop me... yes?"

The mermaid grinned and disappeared underwater. A minute later, Eren was returning to his huge deep sea form, putting his hand on the beach.

Levi hesitantly climbed up and stood on the palm, holding onto Eren's thumb. The mermaid carefully guided the hand to his head where Levi jumped off and gripped the hair tightly.

"Weird... but somewhat cool..."

The giant fish huffed a laugh and swam out to the ocean, leaving only his head above the surface and letting the wind blow through Levi's hair.

They stayed like that for a while until they saw Hanji return. Eren carefully set the raven back down and then went underwater again to reappear shortly after.

"Good?"

"Yes, it was very good." Levi chuckled.

"Looks like you two had fun!" Hanji said as she prepared a fire to cook some fish and crabs. "Eren, you want some?" they asked and held up two fish.

"Yes!" Eren's eyes lit up and caught both fish with his mouth and a lot of skill midair as Hanji threw them.

"Amazing! This is so much better than filming tropical mermaid culture!"

-~-

After eating together, Hanji asked with big eyes and shortly after Eren reluctantly agreed that the scientist could examine him.

She took measurements and then told Levi to pick him up. "Are you fucking serious? Mermaids are heavy as fuck!" Levi growled.

"Only river mermaids are, because of their size and different structure. But Eren looks like straight out of a fairytale, like a human with a fishtail. Just try it, maybe he's light?"

Levi grumbled and gently put his arms around Eren's torso and tail, right below where his ass would be if he would be human. Then he carefully went to pick him up, only to nearly throw him up and away. "HOLY SHIT!"

"What is it, Levi?" Hanji asked, scribbling into her notebook.

"The brat weighs like... nothing. I could lift him with one arm if he weren't so big."

"Whaaaaaat?!" Hanji screamed and dropped the notes, closing the distance and took Eren from Levi's grip.

"H-Hanji?" Eren asked nervously, fidgeting in their grip.

"Okay he's not _that_ light, but compared to other mermaids... He's even light for a human! How much do you think he weighs? 60 Kilograms?"

"Yeah, something around that..." Levi took the mermaid back in his arms and smiled down at him before setting him back into the shallow water.

Eren smiled back that immediately faded when he heard a shout behind him from the ocean.

_"EREN!"_

**Notes for the Chapter:**

> *hides in a corner*   
> I'm sorry for the cliffhanger >->")


	4. Monster

**Notes for the Chapter:**

> If anyone can tell me what language Eren is speaking, they get a digital, home-made cupcake from me!!
> 
>  
> 
> Thanks for all the love in the comments! ♥ It makes me really happy and since you guys are very impatient, it's 30 minutes after midnight so technically friday :D

Eren seemed to pale and turned around.

The three looked out to the ocean to see a mermaid, looking similar to Eren, swimming closer.

"Eren! Etan þa-uχ kuman þu blauþu! Abe-trunne ēnu tugan!" The mermaid shouted, the expression a mix of disgusted and angry.  
_(Eren! Eat them and come here, you Idiot! You renegade good-for-nothing!)_

Eren growled and Levi could see him turning from the curious, cute mermaid into a terrifying creature of the deep sea. "Blauþu hōre! Ik ver-slingen þu!" He screamed back, scaring the two humans silent with how powerful he could spit words.  
_(Stupid whore! I will kill/devour you!)_

"Maþan! Hvwar-þar ik mauja mahal þu..." The mermaid answered, groaning loudly.  
_(You maggot! Why do I pretty thing have to court with you...)_

"Snakan, Ymir Maþan þu!" Eren snapped and brought his hand to his mouth, biting so hard into the flesh that he tore a piece out.  
_(Shut it, you're the maggot, Ymir!)_

Levi watched, completely horrified by Eren's actions until suddenly hot steam surrounded him and a few moments after his deep sea form loomed above them.

The other mermaid quickly bit into her hand as well, though not as brutal as Eren. Before Levi or Hanji could say anything, the two mermaids began to swim towards each other and then attacked.

Eren let out a loud roar before tearing into the other's shoulder. The mermaid responded by clawing Eren's arms bloody and biting at his neck.

"It's that deep sea mermaid that ate the tropical mermaids!" Hanji realized and dragged themselves with Levi back to their tent, still watching the fight. "Do you think he'll win?"

"Maybe. He survived thousands of years without killing, you have to be very strong to do something like that." Levi said quietly.

Hanji hummed and began filming the fight. "He never said that he doesn't kill, though. He only said he doesn't eat tropical mermaids or humans..."

Levi shuddered at the thought of his cute Eren murdering his own species.

"The other mermaid may be smaller, but its teeth and claws are a lot sharper... Let's just hope Eren wins..." Hanji sighed.

"Hragjan, Eren! þu werþan ek volen-uχ Ik werþan þu nawi frezzan!" The mermaid growled and clawed at Eren's face.  
_(Wake up, Eren! You will fill me and then I will feast on you!)_

Eren roared louder and bit harder into the other's shoulder until the mermaid's arm was bitten off and fell into the water. The brunette roared again, showing dominance and snapped his mouth after the other mermaid, who now took her leave in fear.

"Nikza! Dula nikza!" With that, the mermaid fled into the depths of the ocean.  
_(Watermonster! You crazy monster!)_

Eren let out a final, agressive roar before he began steaming and let himself sink underwater, only to come up in his smaller form.

"þu þan beost! Ik cwellan þu!" Eren screamed after her with all his voice could give.  
_(You're the biest! I'll kill you!)_

"H-He's really scary sometimes..." Hanji laughed in fear, breathless.

"Hey! Eren!" Levi crawled out of his safety spot and ran to the shore, calling out to the mermaid. "EREN!"

The brunette turned around with his murderous look, that instantly disappeared when he saw Levi. He swam back to the beach but looked away in shame.

Levi sighed and rolled his eyes, then stepped into the water and grabbed Eren's hand. "It's... healed?" he quickly looked up at the other's face when he heard a quiet sob.

Tears were rolling down Eren's cheeks. "þu þan blauþu nikza... Ik keen nikza..." he muttered and stared back out to the ocean. "Ik keen nikza..."  
_(You're the dumb monster... I'm not a monster...)_

"Eren?" Levi asked in a gentle tone and turned the head with his other hand to wipe away the tears.

"Levi... Ik keen nikza... I no monster..." Eren cried and fell forward to bury his head in the raven's chest.

Levi's heart ached from Eren's cries and he quickly hugged the mermaid tightly against his body. "No. You're no monster, Eren."

"þanka..." Eren whispered and Levi didn't need a translation to know that Eren was thanking him from the bottom of his heart.

Hanji watched them from a distance and turned the camera off. "They're really cute like that. No one would think they're both so dangerous when they want to." they said quietly.

-~-

After a silent dinner with Eren still clinging to the raven, Hanji had gone to sleep and left the two men alone.

Eren was laying on his back, his tail lazily flapping in the shallow water and was stargazing with Levi, who had his arm around the mermaid's shoulders.

Neither of them said anything, just enjoying the sight until Levi felt his eyes getting heavy. Eren turned in his grip and brushed his cheek against Levi's.

"Levi... slēp." Eren said quietly. When Levi opened his eyes again, the mermaid smiled down at him and began stroking Levi's hair.

"Awiz eχwaz-uχ. Awiz, χwesja wulno ne ist, speχet eχwanz, ainan krun wagan wegantun, ainan-uχ mekon boran, ainan-uχ gumonun aχu berontun. Awiz nu eχwamaz weuχet: χert agnutai meke witantei, eχwans akantun weran. Eχwaz weuχant: χluđi, awi! χert aknutai uns wituntmaz: mannaz, foþiz, wulnon awjan χwurneuti sebi warman wistran. Awjan-uχ wulno ne isti. þat χeχluwaz awiz akran bukeþ.*"

Levi fell asleep during Eren's soft speaking and only remembered thinking "I wonder what he's saying... I'll have to ask someday..."

-~-

The next morning, Levi woke up panicking. He was inside a thick, fleshy cocoon with no way out. Before he could shout or scream, Eren brushed his hands over Levi's face and smiled. A second later, the flesh wall began steaming and disappeared. Levi immediately crawled out until he was completely on the beach.

Once out, he saw Hanji beaming at them. "Amazing! This flesh cocoon held both of you inside, with no water for Eren at all!"

"Hanji, please, just shut the fuck up..." Levi sighed heavily.

"Yeah yeah, grumpy-pants. Eren, how're you feeling today?"

The mermaid looked up at the sound of his name. Hanji put a hand to his chest. "Good? Bad?"

Eren thought for a second. "Good?"

"Great! Wanna tell us now who the other mermaid was?" Hanji asked and drew a picture of Eren fighting with the other mermaid, then pointed at her.

"Mate." Eren muttered, his expression darkening.

"I thought... you have no mate?" The scientist asked confused.

Eren nodded pointed at the other mermaid. "Ymir bad mate. I no mate. I have no mate. Ymir bad."

"So... this Ymir wants to be your mate? But you do not want her as a mate..." Hanji thought out loud. "Why Ymir bad mate?"

Eren looked disgusted and drew himself getting eaten by a pregnant mermaid. "No." Then he drew two humans holding hands and kissing. "Yes."

"Aww, you're too cute! I had no idea your species would be _that_ brutal, you guys are like spiders!" Hanji squealed.

"Back off, shitty glasses. If anything, Eren's mine. I'll take care of Ymir myself the next time that bitch wants Eren."

Eren frowned at Levi, hearing names but not understanding the meaning of his sentence. Levi ruffled Eren's hair and then drew himself killing Ymir over Eren's drawing where he was getting eaten.

The mermaid laughed a little at that and pulled Levi into a hug. "Dula homō."  
_(Crazy human)_

"Did... did he just call me gay?"

Hanji broke out into laughter. "Levi, homo is latin for human! He probably just called you tiny human or something like that."

"I'm not _that_ short!"

"But I'm kind of wondering what language Eren speaks anyway, it has latin elements but it isn't completely latin... maybe something older?"

**Notes for the Chapter:**

> * Eren is telling Levi a good night story, here the translation:  
> "A sheep, which had no wool, saw horses, the first pulling a heavy wagon, the other which carried a heavy load and the third which carried a human.  
> The sheep spoke to the horses: "My heart tightens when I see how the humans pushes you horses around."  
> The horses spoke: "Listen, sheep! Our heart tightens at the sight:  
> The human, the lord, makes out of the wool from the sheep warm clothes for him, and the sheep have no wool."  
> When the sheep heard that, it fleed from the field."


	5. Not giving up

**Notes for the Chapter:**

> I'm sorry for the late update TT^TT ♥

The two humans spend the rest of the week trying to teach Eren as much english as possible and Levi spend each day more and more hugging Eren or letting him rest his head in his lap.

The mermaid had explained them that his mate only wanted him because she was in heat and he close by, and that his species wouldn't love like humans, even though he wished for something like that. He also mentioned that Ymir would return soon, after a cycle of eating and sleeping.

So, it was no surprise when she appeared in her deep sea form, roaring Eren's name.

"Ik hrekka Ymir..." Eren growled, but then looked at Levi. "Levi. Hurt Ymir?"

"Sure, where?" Levi immediately responded, not even fully registering how difficult it would be.

The mermaid tapped at his neck and made a cutting motion. "Levi?"

"Okay, let me grab my knife." Levi rushed to get the kitchen knife he brought with him as Eren transformed. He then jumped on the outstretched hand and ran up the arm until he was on Eren's shoulder and held onto the hair.

The other mermaid was swimming towards them, and Eren didn't hesitate to do so as well. He roared and ducked when she snapped after him, sinking his teeth right under her ribs on the left side.

Levi jumped off and onto Ymir when she bit the brunette into the right arm. He swiftly moved to her neck as the two mermaids were holding each other tightly and began stabbing into the flesh.

The smaller mermaid screamed and let go, attempting to crush Levi under her hands, but Eren was faster, moving to hold them tightly and lowered himself right above her neck.

Levi climbled back onto Eren right in time to not see, but still _hear_ the sound of his mermaid tearing into the neck and swallowing several big chunks that were about Levi's size.

"Eren... oh go-" the raven had turned around to try and stop him, but once he saw the sight, turned back around and bend over, throwing up into the sea.

Eren stopped and growled in delight when he saw Ymir steaming, dissolving into nothing. He quickly swam back and carefully put Levi down before changing back.

"Sorry." Eren said quietly and gently rubbed Levi's back once he had climbed the beach.

"No, it's... fine. It's okay. Well not really, but... yeah."

Levi sighed and Hanji stared out the ocean. "Where's Ymir? Did she run away again? You were so far away I didn't see anything!"

"No, Eren... ate her." the raven shuddered at that and tried to not throw up again.

Hanji looked at Eren in disbelief and then pulled both men into a hug. "You boys did fight well, though. Like Eren said, she was bad and probably deserved it."

Levi smiled and reached for the notebook and pen nearby. "Hey, Eren. What does 'good job' mean in your language?"

"You say gōda arba."

"Gōda arba, brat."

"Gōda arba, kleini!" Eren grinned.

Levi frowned a little. "What does kleini mean?"

"What does brat mean?" Eren responded, still grinning.

Levi drew a little child and repeated the word brat, and in return Eren motioned 'little'.

"Yeah, well, of course I'm short compared to a deep sea mermaid!"

"You're still small if compared to a garden gnome." Hanji chuckled.

-~-

"Levi fight good." Eren said a few hours later when they settled down to eat lunch, which consisted only of fruits for the humans.

Hanji nodded and drew a picture of Levi fighting. "He was a soldier."

"No hurt, Levi. Why... stop?" Eren struggled to ask.

Levi sighed, trying to push down his memories. "I was kind of forced into the military, and even though I was one of the best, I only did the years I had to and then quit." he explained with drawings.

Eren hummed in understanding and pulled Levi into a hug. "Sorry."

"For what?"

"Sorry for see Ymir hurt." Eren said softly. "I bad..."

Levi smiled a little. "It's alright, Eren."


	6. Going Home

Levi cooked some fish Eren catched for them, along with fruits when Hanji said out loud what had been bothering them both the last days.

"We can't live forever on fish and fruits, you know? Also, our notebooks won't last long anymore. Someday we'll have to finish filming and go back home..." Hanji noted as she watched Levi feeding Eren with pieces of raw fish.

"I know, Hanji. But what about Eren? We can't just use him like that for research and then leave."

Hanji hummed. "There's no other way, Levi. Besides, if he's over 2500 and still looks that young, then he will outlive us by far as well. He's probably used to people aging and disappearing around him..."

Levi glared his friend down, pissed off. "Yeah, well, I'm used to battles, pain and dying people too, but I still don't want it!"

Hanji winced a little, causing Eren to reach for the notebook and shove it at the scientist. "Hanji."

Hanji sighed and drew the situation for Eren. The mermaid hummed curiously and drew a small earth, then gave Hanji the pen and motioned 'bigger'.

"A map?" Hanji asked and drew a simple version of the world, marking where they were right now. 

Eren suddenly smiled happily and drew another small x at a shore of the north sea where either the neatherlands or germany would be.

"What? That's your home?"

Eren nodded. "Haima." 

Hanji drew a line between the two points with her index finger. "Why the long way?"

The mermaid thought for a second before ripping out a blank page and drawing himself with angry humans next to him with weapons.

"Oh, I see..." Levi said and then drew an x where New York would be. "My home." After a short thought, a drew a circle along the nearest coasts. "Our home?"

Eren's eyes lit up with happiness and he nodded. "Yes. Good home."

"See, shitty glasses? No problem. I'll move to a quiet beach nearby with Eren, and you can easily visit us."

"Alright lover-boy. Then let's plan our trip back, because we don't have a boat to take the water route and Eren can't walk on land."

Levi smirked and drew Eren with him and Hanji on top. "We have a boat."

Eren and Hanji looked at each other, blinked several times, and then broke out into laughter. 

"That's perfect!" - "þa goed!"

The mermaid stopped laughing first and thoughtfully looked back at the map. "Äh... Levi?"

"What?" the raven asked, raising an eyebrow.

Eren began blushing and took Levi's hands into his. Hanji carefully backed away to look over her notes, letting them have their moment.

"Eren, what is it? You can talk to me. Do you need the notebook?" Levi nodded with his head towards the notebook.

"No..." Eren sighed softly. "Levi. You have mate?"

Levi tilted his head. "No, I have no mate."

"Levi.... mate Eren?"

The brunette's blush crept down all the way to his chest.

"Eren... I... Well... fuck it. Yes I want you to be my fish boyfriend." he paused, beginning to blush as well. He shut his eyes tightly and pulled Eren into a kiss. It took the mermaid a second but soon the kiss was returned and they only pulled away to catch their breaths.

"Home?" Eren asked, pointing at Hanji already packing her things excitedly.

"That shitty glasses." Levi hissed and ruffled his new mate's hair. "I'll be right back."

Hanji was already finishing packing her own belongings when Levi had walked over. "We can't just leave like that, we won't have enough food to make it back if we go now, you know?"

The scientist simply grinned in return. "I'm sure Eren can get us some fish and I still have vitamin pills to prevent us getting too sick!"

"This is completely crazy, even for you."

"I know! That's the fun about this mission! It'll be a really tight fit to travel back, even with enough food we're as good as dead if Eren meets rivals or a heavy storm hits us. We could only survive a few minutes in the water itself and if we fall off we die the second we hit the ocean."

Levi glared at his friend and sat down in the sand. "Even a small boat wouldn't protect us from these dangers except maybe drowning, so the biggest problem would be us falling off. We can't tie us to his body or anything."

Hanji hummed and looked over to Eren, who was currently playing with small crabs. "Maybe Eren has an idea. He said he had human friends before, so maybe he's done something like that before?"

"There's also the possibility that he didn't flee alone from his home..." Levi thought out loud and so the two of them finished up packing their things before sitting down next to Eren with the notebook and pen.

Hanji drew a picture next to the last picture of them riding on Eren's back where they fall off. "Any ideas?"

Eren frowned a little and thought a short while before drawing him with something similar to a submarine on his back and clearly struggled to explain. "Human, äh, tidi. No Levi, Hanji. Human Mikasa, Armin."  
(Human, uh, from the past.)

"I see... but we can't build something like that, we don't have the materials." Hanji sighed and scratched the back of their head.

Eren groaned and rubbed his face. "þa keen baita. Ik þa baita, júz blauþu!" he muttered in frustration, picked up the pen but also dropped it several times.  
(That's no boat. I'm the boat, you idiots!)

"Seems like you can't draw everything." Levi sighed and gently put his hand on the mermaid's shoulder.

Eren huffed and tried again with signing. "I... baita." he repeated and pointed at himself, then at the drawn boat on his back.

"Eren, sweetie, we know you can carry it, but we can't build it without materials!" Hanji explained, also with gestures.

The mermaid faceplamed and then bit into his hand, but only transforming one arm. Then he concentrated, and something grew on the flesh that looked like a crystal. He carefully formed it into shape like on the drawing. "I baita." he said a third time, with a certain annoyed tone in it.

Hanji gasped at the sight and crawled closer to the giant arm, poking at the crystal. "It's hard as a rock! If Eren can make it big enough that we can fit in it, then we can actually make it!"

Eren looked at the human's bags in the small distance and hummed before making the motion for 'bigger'.

"We don't have more, Eren." Levi said, slightly confused.

The mermaid shook his head violently, looking at them horrified. "No, you maizan etan!" he hurried to say and signed 'bigger' and 'eating'. To prove his point he drew with his finger a line on the map Hanji drew before from their mark along South America and then up to where New York was marked.

"Ah, no Eren, we won't take the long way, there's now... oh. I suppose if we travel through the panama canal we will be a bit suspicious."

"Can't we somehow make the trip through Panama on land? We could try and somehow carry Eren in a water container." Levi questioned.

"Maybe we can rent a pick-up and fill out the back with tarp, then pour water in. Only problem with that is, the drive will take a few hours and the weather there will heat up the water and I don't know... Eren's used to deep, cold water, not hot puddles."

"Tch, this will be a lot harder than we thought." the raven hissed.

Together, Levi and Hanji tried to explain their current plan to Eren and the mermaid paled a little at the last part with the tank before he slapped his hand against his forehead again, murmuring to himself. "Ik swē blauþu!"   
(I'm so stupid! / I'm such an idiot!)


	7. Deep Waters

**Notes for the Chapter:**

> Am I too late with the update? Yes? No?
> 
> I don't know anymore, time is slipping out of my hands I have no idea which day it even is... ¯\\_(ツ)_/¯  
> (I'm very sorry if I'm late though!!)

Eren reached for the pen and drew himself in a crystal. "No water."

Hanji grinned and then began to draw to explain her question. "That's a great idea, how long can you survive in it?"

The mermaid thought for a second before shrugging. He took the pen from Hanji and drew another mermaid in a crystal. He pointed at her. "Annie." Afterwards, he drew a human baby and a teenager.

"So this Annie was in the crystal for years?" Hanji asked with Eren nodding in return. "Amazing! How do we tell you that you can come out?"

"Water." Eren simply said and pointed at the ocean. "I in water."

Levi raised an eyebrow. "We just throw you in the ocean?" he asked and acted like he threw something in the water.

The mermaid nodded again and smiled. "Yes. I am fine."

"Then let's go!" Hanji squealed.

Eren looked up and shook his head, then made a line to where the sun goes down at the horizon.

He made a motion for sleeping and pointed at the horizon where the sun goes up.

"Need sleep. Good night, Hanji, Levi." Eren smiled and gave Levi a small kiss on the cheek before swimming into the deep water.

-~-

"Good morning, Eren! Did you sleep good?" Hanji asked and ran to the shore when they spotted the familiar brown hair breaking through the water's surface.

"Yes, you?"

"I slept good, too! But Levi didn't, he's so worried! It's so cuuute!"

Eren only smiled and then waved at Levi to caught up carrying the bags. "Levi, Hanji?"

"What is it?" Levi asked when he reached them and stopped to kiss Eren's forehead.

The mermaid sighed. "Be-ginnan wíz?" he said and pointed at the sea behind him.  
(Ready to go?)

"We're ready, Eren. Let's go." The raven placed another kiss on Eren's lips.

Eren smiled happily into the kiss before pulling away and inhaling deep to scream. "Wíz ubar-sigirōn!"  
(*victory shout for good luck*)

Hanji joined the scream that just made Levi shake his head in disbelief.

Then, the mermaid bit hard into his hand and Levi flinched when blood went everywhere, even his face. But before he could feel disgusted, he saw the blood steaming and vanishing.

"Amazing!" Hanji giggled while Eren concentrated and build up the crystal on his back. Then the giant gently grabbed the humans with their luggage and let them inside before sealing it.

They had agreed that Eren stops every 12 hours and open a part of the crystal to let air inside and that it would take them about 2 days to reach Panama and after crossing the land another 3 days until they would reach their destination. In emergency cases Eren told them to stab him with a small knife, so that he knows to go up.

With a roar, Eren pushed himself into the water and swam with incredible speed forward and down into the depths of the ocean.

"Levi, this is so amazing! I mean, even though he sinks down so quickly we don't feel anything of the pressure! I can't believe that this a organic material, and how did he produce that?!"

"Shitty glasses. We won't have enough air like that. Calm down and look outside or something."

Hanji sighed and pressed their face against the crystal to look down as far as possible. "I wonder how deep he can dive, it keeps getting darker..."

Then, a silence spread out inside the crystal for a few minutes as they both grew anxious with how deep they went.

"Levi, not to disturb you, but... we're entering the midnight zone, and Eren is still swimming downwards. We will have to turn our flashlight on soon or we could damage our eyesight spending so much time in darkness."

As if right on que, Levi and Hanji were surrounded in a soft yellow/greenish light. They looked around to see that Eren's lighter spots began to glow in the darkness.

"L-Leeviiiiii!"

"I can see it, Hanji. Now stop screaming..." Levi said but the amazement and partly fear was clear in his voice. 

And that fear only grew in both of the humans as the mermaid continued to sink deeper and deeper until finally Eren stopped to swim down but increased his speed forwards in a straight line.

Hanji gasped and grabbed Levi's arm tight. "Leviiii, the fish around us..."

"What about them?"

"These are mostly species found near the bottom of the ocean, on the actual fucking ground of the ocean! That means we're thousands of meters below the surface, no mammal can dive that deep!"

"WHAT?!" Levi shouted, trying very hard to not panic.

Hanji's switch quickly went from her excited mode to her actual professional mode and pulled the raven into a loose hug. "It's alright, Levi."

"What do you mean with 'it's alright' shitty glasses!? We're at the bottom of the ocean! If anything happens Eren can't just quickly swim to the surface and let us _out_ of this thing! We're trapped here inside and, and if we notice the air- oh god the air we will die in here-"

Hanji sighed and punched Levi in the face. "We fucking won't die, Levi! I even packed oxygen containers in case something happens, the air in the tubes can last long enough to get us back safely. And I'm sure that if this whole thing wouldn't be safe then Eren wouldn't have done this several times to transport humans."

Levi calmed down a little and evened out his breath. "How did you bring oxygen down here?"

Hanji grinned and patted on one of her bags. "I packed some to dive with the tropical mermaids, of course!"

"I'm glad you're so crazy sometimes..." Levi commented with a soft smile.

Hanji giggled. "Awww, I love you too, Levi!"

Levi only snorted in return and opened one of his bags to pull out a book to read. "I have an awful feeling that this trip will quickly become very boring..."

The brunette laughed. "Maybe. We could always write reports for our dearest Erwin~!"

"Yeah... I think it will be boring, but not _that_ boring, Hanji."

The scientist laughed a little and looked around. "Who would have thought that we're on a adventure like this right now? Deep sea mermaids are simply incredible!"

"And Eren is the most incredible of them all..." Levi muttered with a soft smile and a little blush on his cheeks.


	8. Land in sight

"Levi!"

Levi hummed, reading a book. It had been a few hours since the last time they had come to the surface but suddenly Eren began to swim upwards again.

"I think we're near Panama!" Hanji said, filled with excitement.

"Fucking finally... I'm slowly becoming insane in here."

Hanji thought for a second. "It really was intense, to imagine that others travelled this way for at least a week, that's crazy! Maybe we can leave Eren in a crystal longer and drive back all the way back to New York?"

"We'll ask him if he's okay with it, I'd prefer any road trip over being at the bottom of the ocean."

Hanji sighed and looked outside. "Yeah, it's cool but the uneasy feeling doesn't go away. I guess we're land creatures after all!" they laughed.

Levi shrugged. "I guess so, the darkness fucks up my sleeping cycle too."

-~-

When they surfaced, the shore was only a few meters away. Eren carefully dragged himself onto the rocks and dissolved at the same time the top of the crystal.

Levi and Hanji climbed out and Eren gently puts them on the ground before pushing hard enough against the shore to do a backflip into the water.

A minute later, Eren surfaced again and held onto a rock as he smiled at the humans.

"Gōda arba, brat."

Eren nodded, huffing out hot steam as breath.

"Eren, are you alright?" Levi asked with concern and sat down, pulling the mermaid against his chest to hold him above the water.

"Yes... Tired." The brunette said, eyes heavy and about to close.

Hanji stepped closer and showed Eren a drawing. "Eren? Is it okay if you stay in a crystal until we reach New York? Maybe that won't take such a toll on your body like carrying us?"

"Yes... good. I sleep..." Eren murmured, buried his face in Levi's chest and it didn't even take him a minute to fall asleep.

Right when Levi was about to say something, the crystal substance grew around him and eventually the raven had to pull him onto the land and let go until the mermaid was covered in several centimeter-thick layers.

"I guess the trip really wore him out," Hanji commented and helped Levi pulling Eren completely out of the water. "I'll try to call Erwin and make him get us out of here."

Levi agreed and watched his mermaid while Hanji called and Erwin sent his nearest people to get them.

"Alright! Jean will come get us, he's in Mexico so it won't take _that_ long. And I even settled some things with Erwin for when we get back!"

"How much did you tell him? I swear if-"

"We won't treat him like an animal, Levi. Don't worry, the most we'll do is give you money to let us speak with him and maybe film some footage for documentaries."

"Ugh, alright. But Erwin's going to pay for the house."

Hanji laughed. "Wouldn't have thought anything else from you, Levi!"

-~-

"That looks like Jurassic Park. Only that it's a mermaid and not a mosquito..."

Levi rolled his eyes and began loading Eren into the back of the pick-up. "Thank you for that important comment, Kirschtein, just what would we do without you? Now shut the hell up or I'm leaving you here behind."

Hanji slapped her hand on Jean's shoulder and giggled. "Don't you think he's so much nicer than before the trip?"

The young man scratched the back of his head. "For the his standards, he really is. What happened?"

Hanji only grinned as answered and hurried to get into the car.

Jean shrugged and climbed into the car. "So what exactly _is_ in the back?" he asked as he started the engine and began to drive.

"It's a deep sea mermaid, shitty glasses and I found out that these species are like underwater titans."

"T-Titans? Like the human eating monsters from the children stories??"

"Exactly! But don't worry, our little Eren won't eat you, he's nice!" Hanji answered.

The young man raised an eyebrow as answered. "Because he's in this weird shell?"

Hanji laughed out loud. "Oh no, Eren's only in there for easier transport on land!"

"Okaaaay.... weird. Wait, weren't the Titans in the stories giants?"

"Eren has another form where he's over 15 meters tall, but we have no idea how he shifts! It's really interesting, you see-"

Levi groaned and held his face in his hands. "Now you've started it, Kirschtein. The shitty glasses probably won't quit with her theories until we've reached New York..."

"S-Sorry."

"Don't talk over my heads, guys! Anyways, what I wanted to say was, Eren bites into his hands which apparently triggers the shifting and then steam starts to appear and he's a giant. The question is, where does all this flesh come from and where does it go when he shifts back? Secondly, he's extremely fast for his size, and unbelievably light as well. So I think it isn't real flesh. I wanted to examine it, but the flesh just disappears if it disconnects from Eren!"

"I'm really sorry..."

Levi looked outside the window and gently leaned his head against the glass. "Just shut it, you idiots."

"Levi really changed, am I right? It's so adorable!" Hanji leaned in to whisper in Jean's ear.

"I think he'll kill you if you ever say that to his face. But one question, though. Why do we have a deep sea mermaid in the back if you guys wanted to study tropical mermaids?"

The scientist sighed and put their hand on the young man's shoulder. "We actually had found a group to study, but they got killed and eaten by a deep sea mermaid called Ymir, Eren saved us, and we somehow ended up studying him instead. You have to imagine, we have to teach Eren english since he doesn't speak it, he speaks-"

"Alright, alright. Thanks for telling me." Jean said quickly enough to stop the endless stream of Hanji's words, turning on the radio and snorting.

"What's so funny, Kirschtein?" Levi grumbled from his spot against the window.

"Nothing, it's just... it's Ocean Man playing, quite ironic don't you think?"

"Whatever..."

-~-

"You've been staring at him for hours, come inside already," Hanji said in the evening. They had decided to stay the night in a hotel, but Levi only silently got to the back of the car to sit next to Eren.

"We can't leave him like this, shitty glasses. If others see him, they could want to steal and sell him. We can't risk that, so I will stay."

Hanji grinned a little. "So you will miss the opportunity to... get aaaall nice and clean? Just like that?"

The raven only glared darkly at her in return, but made no signs of moving. Hanji's eyes widened in disbelief at that and sat down in the back of the car as well.

"Alright, I know you itch for a proper shower. I'll watch over him and you go get cleaned up, okay? Afterwards, we can just chill out here, it's not like we can't sleep in the car tomorrow!"

"Don't even blink, if something happens I'll rip your eyes out and shove them up your ass." Levi hissed, but somewhat pleased got up and headed to their room for a long, hot shower.

A few minutes later was Levi standing under the stream, thinking about the situation he was in.

_'Why am I even getting so worked up about Eren? And why did I agree to be his mate just like that?! I barely know him and he barely knows me... This is just bullshit!'_

Levi lightly punched the shower wall and turned off the stream.

_'It's not like I can stop now, the little shit really tore its way into my heart... fuck, that's so cheesy!'_

Slightly frustrated, he stepped out and dried off before getting dressed in a comfortable sweater and pants.

By the time he returned, Hanji finished a phone call and looked at Levi with sad eyes. "Levi, we have a serious problem. A really huge fucking problem."

_'Oh fuck no... When shitty glasses starts swearing, then you know shit did hit the fan and it's a huge beer-shit.'_


	9. Big fish caught interest

"Fucking shit..." Levi cursed under his breath and stepped closer. "What is it?"

Hanji sighed and looked away, struggling to find the right words, which was rare for them and made Levi's worries only grow.

"There was some... interest in my idea of a documentary of tropical mermaids, and they asked Erwin what's going on. He had to tell them everything and... well... let's say the real big fish caught interest in Eren."

Levi thought for a second, connecting the pieces and processing what Hanji told him. "Are you trying to fucking tell me that the _damn_   _government_ shits all over our plans?"

Hanji nodded, still not looking up. "Erwin got ordered to hand over Eren 'for both their and our safety'. And since it's technically illegal to catch and keep wild, endangered animals our cards look bad."

"EREN ISN'T SOME FUCKING ANIMAL!" The raven shouted at the scientist, though he knew in the back of his mind that Hanji was aware of that fact.

"He isn't some fish to put in an aquarium and maybe even have kids push their snotty noses against the glass! What a load of complete shit..."

Hanji finally turned around and stood up to hug the male against their chest.

"I know... It's unfair and just plain stupid, Levi. But there's nothing we can do. We were told to drive to the nearest airport where a machine will pick Eren up and transport him to Washington. We're told to return to New York and report everything to Erwin and if we don't cooperate... well, then we're even more fucked."

"Why did I think in the first place that bringing Eren with us is a good idea...? You were right, shitty glasses, he would be better off without us..." Levi sighed and relaxed a little in Hanji's arms.

"Don't worry Levi, we will get him out somehow. Hopefully legally, and illegally if we need to, okay?"

Levi broke free from their grasp and glared at the scientist. "Help me get him inside. He deserves to know what's going on and there's a bathtub in the room."

-~-

With that, the two of them carried the heavy crystal into the room and then inside the bathtub. Afterwards, they turned the water on and put two chairs from the living room to the bathroom next to the tub.

It took a few minutes until the water had nearly filled the whole bathtub and the humans saw how slowly the crystal dissolved in the water. They waited a bit more until the mermaid was completely free and slowly opened his eyes.

Eren sleepily looked around the room, taking in the surroundings. He blinked in confusion until he saw Levi and Hanji looking at him.

"Levi, Hanji," Eren spoke quietly, sounding halfway asleep.

"Hey, Eren. Sorry to wake you so soon, but something happened..." Hanji started and began to draw pictures to show Eren what was going to happen to him.

The mermaid's eyes widened and stared unbelievingly at the pictures. "A-Aba... Levi... we mate!"

The raven looked down at his intertwined hands, that he squeezed tightly. "I know, I'm sorry, Eren."

Silent tears began to roll down Eren's cheeks, the only sound in the small bathroom being them dripping from the mermaids chin into the water of the tub.

"L-Levi... Ik weljan bi-līban medi þu. Ik furtha ễnu þu... P-Please, Levi..." Eren sobbed, trying to wipe away his tears with his palms.   
(L-Levi... I want to stay with you. I'm scared alone... P-Please, Levi...)

Levi got up from the chair to kneel directly next to the tub and gently pulled away Eren's hands to look at his mate properly.

"Hanji, draw something to tell him that we're definitely going to save him. Eren, look at me." he paused until he could see teal eyes focusing on him.

"Eren..." he started but stopped again, at a loss of words the mermaid would understand. Instead, he leaned in and showered Eren's face with little kisses, occasionally the eyes to get rid of the tears. After a few moments, Eren somewhat calmed down and giggled a little when Levi discovered a spot where Eren was ticklish.

Hanji then showed Eren her picture and made him understand that they would rescue him as soon as possible. The mermaid nodded and reached for the pen and paper and for the first time, didn't draw something, but wrote down words and drew Hanji beneath it, translating the words and smiling afterwards. He knew they were very interested in his language and could find a way to translate properly.

The scientist smiled and nodded. "I'll be able to translate this back in my office. Thank you, Eren."

The mermaid hesitantly smiled back and turned back to Levi to kiss him sweetly on the lips. "I love you, Levi."

Levi teared up at that as well. "I love you too, brat."

"Kleini!" Eren grinned and grabbed both sides of Levi's face to pull him into another kiss.

"I think I'll leave you two love birds alone and go play cards with Jean or something." With that, the scientist disappeared from the bathroom and left the two males alone.

The raven wasted no second and attacked his mate's lips passionately. The brunette moaned into the kiss when it started to deepen and clutched to Levi's shirt in an attempt to pull him ever closer.

In return, did the human slip one hand into Eren's hair and the other held onto his waist. "I don't know if I move too fast for you, Eren... And I want to take things further..." he sighed needily, his voice clearly displaying his lust.

Eren must have heard it through, if his blush was any indication. He smiled a little and Levi saw his mate's cute puppy eyes change in an instant to sexy beast mode. A shiver ran through Levi's body.

"Levi..." The mermaid whispered in a way that made Levi immediately half hard.

The brunette then slid down and gently bit and sucked at Levi's neck, causing the man to moan.

"Fuck, Eren, what are you, a sex god!?"

The mermaid only chuckled darkly in return and ran his tongue up to the human's jaw. "Levi, Ik weljan þu."   
(Levi, I want you.)

And even though Levi had a pretty good idea of what Eren said, he tried to seductively say it in english as well, his lips hovering near Levi's ear, softly kissing the shell.

"I, you, mate."

Levi started to go red all the way down to his neck and took a good look at Eren and wondered how he got so lucky to have him as his mate until he remembered that it wouldn't last long.

He nodded as an answer and the hand from Eren's hip slid down to where a human crotch would be, only to find a small slit, but the mermaid moaned and shortly after something pushed its way out that strongly reminded Levi of a dick.

"Fuck, you really don't have any weakness, huh?" Levi huffed as he ran his hand over it, feeling the length.

"Levi... þu witan Ik ễnu witan þu wurda..." Eren laughed lightly and let his own hands slide down until they reached their destination and worked to open and pull down Levi's pants and underwear.  
(Levi... You know that I don't know what you're saying...)

"Do I even want to know how you know how pants work?" Levi asked more himself than Eren and tried not to buck into the hand that cupped him after Eren's success of undressing Levi.

They began to slowly stroke each other's member and after it proved to be a little difficult Levi decided to climb into the tub, his legs pressed against each side of Eren's tail.

The two males quickened their pace and moaned sweet little nothings in their native language at each other, losing themselves in the sensation until they reached their climax.

"Fuck, Eren, Eren, ERENNN-" Levi moaned as he came all over Eren's stomach, while Eren just screamed Levi's name once before coming hard too.

"That... that was... hot." Levi panted on top of Eren, smiling happily.

The mermaid grinned back before looking down and scrunched up his nose a little. "Bad water."

Levi looked down as well and agreed. "Yeah, it's probably not a mermaid's dream to swim in cum. Hold on, let me just..."

He stepped out of the tub and was ready to pull out the plug when Eren pushed himself out of the tub and snuggled up against the rug, looking at Levi with wide eyes.

"That's even better. But don't dehydrate on me here." Levi murmured as he let the old water go down the drain before pushing the plug back in and started to fill a new tub.

The mermaid curiously looked at the technology that was completely new for him with amazement and crawled closer to play with the stream of water.

And after Levi showed him how to operate the tabs, Eren turned it impressively cold before pulling Levi down with him on the rug and began to cuddle with him.

_'Shit, he's so cute... How will I survive even a day without him...?'_

**Notes for the Chapter:**

> You thought the chapter would be all bad and mean, but no my friends, it was light smut! :D  
> (This chapter has been made thanks to hardbass and cheeki breeki)


	10. Seperated

The next morning, Hanji and Jean walked into the bathroom Levi and Eren shared to see Levi sitting on the floor in front of the tub, with Eren fiddling with something on Levi's neck.

"So that's Eren breathing and shit? Looks more like Arielle than a scary deep sea monste-"

Jean interrupted his sentence when Eren shot him a sour look that could kill and untangled one hand to flip him off.

"I taught him that," Levi explained, sounding quite proud.

While Jean just shook his head, Hanji stepped closer curiously. "Anyways, what are you guys doing?"

Eren switched back to his happy look and pulled the string around Levi's neck up to reveal a necklace with 4 fish scales arranged into a diamond shape at the bottom.

"Eren made me a necklace, obviously. The bastard ripped the scales out like it was nothing and even wanted to use his fucking tendons too, but luckily I found some strings lying around."

"Creepy... I'll just... wait in the car." Jean stammered and hurried out of the room, but Hanji squealed in delight and examined the necklace.

"Amazing! It looks really good, Eren! How're the scales attached?"

Eren blushed a little in embarrassment from the compliment and Levi explained that his mate used his crystal abilities to glue everything together.

"It's truly beautiful... But, we have to go now. Say goodbye and make him turn into the crystal again, alright?" Hanji said in a sad tone before smiling warmly at Eren. "See you soon, Eren!"

The mermaid nodded and waved in return, feeling anxiety rise in him and his hands starting to shake.

-~-

Levi stayed with Jean inside the car when Hanji helped officers loading Eren into a small, military looking plane.

"I suggest you get a big tank for him, he can get up to 15 or 20 meters outside the crystal, which dissolves in water. And please, consider that he's not some animal, he has feelings and everything."

The men dismissed them with a short nod and just left Hanji standing there as they shut the doors and made everything ready for the flight. The scientist sighed before getting in the car and motioned for Jean to start driving to New York.

-~-

As soon as they arrived, was Levi heading to Erwin's office to go over their plans of getting Eren back while Hanji headed to her own office to try translating Eren's note.

_'Aina skehan fanē mīna mōder:_

_Aina mēla junga kinþa-uχ, ganisan-uχ gōda, þa kinþa etan uftō daga-uχ i gōda kinþa._  
_Aba aina daga, i brimman i etanmēla i weljan._  
_I þu-gannen ningeln "Ik ni etan þa-uχ, Ik weljan aina anþara!"_  
_Uχ sehwan þa neuja daga, i sehwan maungen. Aba i þu-gannen ningeln "Ik ni etan þa-uχ, Ik weljan aina anþara!"_  
_Uχ sehwan þa neuja daga, i sehwan maizan maungen. Aba i þu-gannen ningeln "Ik ni etan þa-uχ, Ik weljan aina anþara!"_  
_Uχ sehwan þa neuja daga, i sehwan maizan þunnu twikkan, ni-kinþa. Aba i þu-gannen ningeln "Ik ni etan þa-uχ, Ik weljan aina anþara!"_  
_Uχ sehwan þa neuja daga, nū aina staina eup i graba. Uχ nū i ni-ningeln eup i etan._

_Mīna mōder sagjan mī þa skehan mēla Ik ningeln eup etan-uχ Ik ningeln uftō mēla Ik junga knab.'_

"The letters are mostly latin, but the language itself isn't. If it's not some mixed language, then it's probably like I already guessed, something older. I wonder if I still have these books about old european languages... Aha! Found it!"

Several hours later, Hanji was so lost in translating that they barely noticed the knock on the door before it opened.

"Hey, shitty glasses. Anything new on your side?"

"Yeah, only a few more words." Hanji nodded and motioned for Levi to sit down on a chair in front of her desk, not even looking up.

Levi silently looked at the horrible handwriting the scientist had and wondered how they could read it themselves. Then he looked at the note Eren wrote and suppressed the urge to groan since a mermaid probably couldn't write often. The handwriting looked like one from a child, only a little smaller.

The man's thoughts were interrupted when Hanji began laughing hard, pushing her glasses away to wipe away forming tears.

"What did the brat write?"

Hanji grinned, her laughing slowly dying down. "The best story I've ever heard! Here, read the translation."

Levi reluctantly reached for the paper and read through Hanji's cliché doctor handwriting.

_'A story from my mother:_

_There was once a boy, healthy and good, the child ate his food every day like an obedient child._  
_But one day, he decided that his food wasn't what he desired._  
_So he began whining "I don't want to eat this anymore, I want something else!"_  
_And look at him the next day, he looked thinner. But he still began whining "I don't want to eat this anymore, I want something else!"_  
_And look at him the next day, even thinner. And he still whined loudly "I don't want to eat this anymore, I want something else!"_  
_And look at him the next day, he looked more like a thin tree branch, not like a boy. But he still began whining "I don't want to eat this anymore, I want something else!"_  
_And look at him the next day, now a stone on his grave. And now he didn't whine about his food._

_My mother told me this story whenever I whined about my food and I whined quite often when I was a little boy.'_

Levi snorted and shook his head. "I can almost imagine a little Eren wanting to have his way... Cute..."

"Isn't your mermaid just a precious little thing sometimes?" Hanji giggled. "The story makes me curious about his family, though.... Anyways, how did the meeting with Erwin go?"

The raven smiled fondly when he thought about his mate before answering. "We have a plan. We're going to get an official paper to state that Eren is not some fucking animal and has the same rights as a human or mermaid, making him not a possession, but an employee in Washington. Then, you'll translate and send him a letter explaining how he can quit his shitty job and apply for a job as your assistant. You'll accept and boom, we have Eren back."

"That's brilliant!" Hanji clapped her hands together. "But such papers could take a while until they're accepted..."

Levi nodded and absently rubbed over the scales of his necklace. "Most likely weeks..."

-~-

With a splash, Eren woke up in the crystal with water surrounding him and slowly let it dissolve. When he opened his eyes, he could see that he was in a huge tank, probably designed for whales. Three white walls and a glass wall were around him, completed with a glass roof and blue floor.

He quickly noticed several men standing in front of the glass with clipboards, watching him closely. In a moment of slight fear, Eren turned away to bite into his hand and transform.

Eren felt more confident in his bigger form and sank down to the bottom of the tank, staring at the men with his spots and eyes glowing brightly in defense.

But there was barely any reaction from them, as they only began to write things down and continued to observe him.

The mermaid let out a small confused growl, frowning at them. Then he looked away for a short while to look around the room he was in, but there wasn't much to see either. It was mostly empty with white walls, except some tables with computers and chairs, as well as some metal wardrobes.

He looked back at the men to see them talking, but the sound of them not reaching his ears through the glass. Eren felt his ears twitch, straining to hear something else than the weird whirring sound from the tank bottom and himself.

Eren folded his arms around his front and half buried his face in the free space, making a low whining sound and wishing that his mate would get him out soon.

**Notes for the Chapter:**

> Before you're wondering what the fuck is that story, it's one of my own favorite goodnight stories as a child and one of the oldest I could think of :D 
> 
> Original is called "Die Geschichte vom Suppen-Kaspar" - story with pictures on page 21  
> http://www.gasl.org/refbib/Hoffmann__Struwwelpeter.pdf


	11. Holding out for a hero

**Notes for the Chapter:**

> Very early update this time. One of my best friends has been hospitalized today and I'll visit her tomorrow so I won't have much time to update and I also want to take off my mind with a new chapter for now... 
> 
> So yeah, early update with our little muffins struggling with the bad, bad government! Enjoy <3

"The specimen looks healthy, but we can't be sure until we run some physical tests." One of the scientists stated, making the others a bit nervous.

"You can see him being stressed in the tank. He might lash out if we provoke him."

The third man nodded in agreement. "Let us contact the Survey Corps since they found this species somewhere in South America and transported it here."

-~-

"Erwin, how're the papers going?" Levi asked without a greeting when he walked into the office.

"Good morning, Levi. You ask me that every single day, but our request is still being checked by the government." the tall blonde man answered, wanting to speak more when suddenly his phone began to ring.

"Survey Corps, Erwin Smith speaking."

Erwin made a motion for Levi to sit down and hummed. "I'm myself still awaiting the reports. But I have Mr. Ackermann here, he was with Dr. Zoe... yes. Yes. I understand. Of course." With that, Erwin handed the phone over to Levi.

"What?"

_"Good morning Mr. Ackermann. This is the official mermaid department speaking. We would like some information about the new specimen you found. We want to check the vitals of it, but we fear it might lash out due to its stressed behavior and-"_

"How and why the fuck did you, fuckheads, even stress him in the first place?!" Levi exploded instantly, hissing into the phone.

_"We just wanted to ask if you somehow tamed it and how you managed to get it smaller and crystallize, alright?"_

"Okay, now for idiots. He isn't tamed or some shit like that, we met him like you asshole meets other assholes on the street every fucking day. He's a fucking mermaid like the other fishdicks."

_"Please excuse us, but he made no signs of being an intelligent being so far."_

Levi groaned in response. "Well, what did you say to him?"

_"The tank is soundproof."_

"That's fucking torture! Go to him, his name is Eren by the way, and communicate. How the fuck would _you_ feel waking up in a soundproof cage with people staring at you?! No wonder he's stressed! And do it fucking now!" Levi finished his rant and hung up, huffing angrily.

"You really care about him, don't you?"

"Fuck you, Erwin. I can't believe these assholes!"

-~-

The scientist walked up to the big tank and waved at the giant mermaid hesitantly with a smile.

The mermaid only glared at the man with eyes that could nearly kill. A shiver ran down the scientist.

_'How the hell did this rude piece of shit of a man get through to this creature?'_

With a deep sigh, the man ruffled his hair and called in his colleagues. He dressed in a diving suit until the other researchers arrived and they observed him slowly climbing up a metal ladder and opening the glass of the roof enough to fit in.

"The mermaid doesn't harm humans, that's what Mr. Smith just assured us by calling again!" A scientist shouted at the diver right before the man jumped in the tank.

Eren flinched a little when he saw the human approach him with several devices and panicked. Everything was still so new, even after days in the tank, his eyes burned from the harsh artificial light, his nose burned with foreign scents and his ears screamed at him to stop the weird, mechanical noises. Even the water was too warm, tasted weird and set him off. The mermaid just wished he could get out and back to the ocean with his mate by his side.

When the human began to poke him with metal things, breaking his skin, he shrieked and without thinking, pulled away to swallow the human whole. He swam to the opening and pulled the diver out of his mouth and out the tank. He then spitted out the devices against the glass and swam to the corner furthest away from the scientists, curling into a ball with his hands over his neck and hardening them.

"Like hell he's intelligent!" The man hissed as he got to his feet and tried to come over the feeling of being in a giant mouth for a second. "That fucker was just having his damn revenge that we got his prize trophy or something..."

-~-

Days came and went painfully slow for Levi. He should've felt some happiness being back at home and sleeping in his bed, but his mind was occupied with worrying over Eren. The people from Washington never called again, and Erwin only asked to hand over the report from Dr. Zoe.

Levi stopped visiting Erwin's office daily after the first week and practically began hiding in his home. Hanji dropped by every now and then with groceries and to comfort the raven. The scientist barely told Levi about what they knew about Eren's condition and it seemed that since the incident with the diver, Eren stopped moving entirely or at least the government's scientists never updated them what happened afterwards.

"Hanji, it's been over a month... I can't take this anymore..." Levi said, trying to hide his tears by lowering his head on his knees.

They were currently sitting on the couch in Levi's apartment, drinking through their second bottle of wine.

"I know... But we did everything we could, Levi. Only a bit longer and we'll get Eren out, okay?"

Levi choked out a sob and curled up tighter on the couch. "I can't imagine what they're doing to him right now..."

Hanji sighed softly and pulled the small man into a hug. "They'll get their punishment when Eren's an official mermaid species. And you two love birds will get your beach house, alright?"

Levi didn't answer.

"Want to re-watch it?" they asked instead, smiling when the raven nodded. Hanji got up to restart their footage from the beach with Eren. The man felt a bit of comfort when he heard his mate's voice but soon felt worse, thinking about how Eren couldn't hear him now.

Hanji stayed until Levi fell asleep before heading back to their office to finish her work. Only a few minutes later was Erwin walking past and stopped to see Hanji at their desk.

"You're still here?"

"No, again. I play Levi's babysitter sometimes so I split up my work time. So, how's it going?"

Erwin stepped inside the office and closed the door before sitting down in front of the scientist. "I got a reply earlier today, our request of making deep sea mermaids an official species is accepted for now, even it won't be published or get into the news yet. I contacted Washington right after and settled things with them, too."

"And the problem is?"

Erwin smiled a little and leaned forwards. "Who said there's a problem, Dr. Zoe?"

Hanji's eyes darkened. "You don't make a happy impression. So, there has to be a problem."

"Sharp as ever... The thing is, Eren's too big to be safely transported over here. And there wasn't a communication problem, he really hasn't moved in weeks. The scientists are impressed how he's still alive, not eating or doing anything."

Hanji sighed, leaning back in their chair, and stared out the window. "Eren's smaller body is nestled in the flesh of the mermaid's neck, so it may be possible that the bigger body provides nutrition for the smaller... And maybe we can cut him out if he can't get out himself, though I believe he simply refuses to."

"They wanted me over there tomorrow to handle the situation. Maybe you and Levi can join me and we will all return together with Eren?"

The brunette grinned. "That sounds like a plan!"

-~-

"Levi! Levi, wake up!" Hanji shook Levi's shoulder, having returned to his apartment after finishing work.

Levi woke up, blinking at Hanji sleepily as he repositioned himself on the couch. "Wh-what is it, shitty glasses?"

"I have 2 good news and one bad." they sang happily.

"Is Eren legal?"

"That's good news numero uno! Second, you'll see Eren tomorrow!"

Levi instantly sat up and stared at Hanji with wide eyes. "No shit? Then, what's the bad news?"

"He's trapped in his giant form and we maybe will have to carefully cut him out. Well, you would cut him out."

"Trapped?"

"I'll explain later. Now, pack your bags, we're going to Washington tomorrow morning!"


	12. Torpor

"As long as we don't get in trouble for letting you guys do this, go ahead. The room is the one on the far right."

"You asshats did _enough_ to get into trouble." Levi hissed at the scientist in Washington before storming into the room his mate was supposed to be in.

Hanji and Erwin were on his heels, but they all stopped when they saw the mermaid curled up a corner of the tank with his eyes closed and hands over his neck.

"Oh shit..." Levi whispered, running towards the tank. He quickly climbed up the ladder and opened the lid. "Eren? EREN!"

"Didn't even twitch..." Hanji said in a worried tone and walked over as well. "Then... can you cut him out?"

Levi hesitated but nodded, opening a pocket at his side to pull out a knife. "Get me one of these oxygen tanks."

After a minute of set up, Levi was able to dive into the tank and swim closer to his mermaid. He tried at first to shake the giant awake, but with no results.

With an internal sigh, he swam towards the neck and first cut off the soft base of the hardened fingers before slowly cutting into the neck.

Steam came out of the wounds and the water temperature rose impressively, so Levi hurried and got Eren's sides and back free without any major cuts.

It was only when Levi tried to pull Eren out, that the water titan showed resistance. The raven pulled harder, hearing flesh being torn and forced himself to look away. After a few tugs Eren came free, and without looking did Levi drag him to the opening. Hanji rushed up the stairs with tears forming in their eyes, causing Levi to wonder why until the scientist pulled the mermaid into their arms and Levi saw Eren's face.

Or, not so much face anymore. The skin around his mouth and nose was completely missing along with his left eye, while flesh from his giant form hung attached to the right side of the face, blocking the eye there. The rest of his upper body and tail was torn as well and pieces of flesh clung to him.

Levi was rendered completely speechless, thinking he might pass out. Erwin stepped into action and pulled Levi out of the tank, while Hanji made their way down the ladder with Eren in their arms.

"This doesn't look good..." Hanji cringed, carefully examining the wounds on the floor. "Weird is, the wounds should bleed like crazy, but there's nothing."

"I... I need some fresh air" Levi said, rushing to the nearest bathroom to calm down and probably give the toilet his breakfast.

"Erwin, ask for a smaller tank to transport Eren in. I'll try to tend to his wounds." Hanji ordered, switched into professional mode and ignoring commanding ranks.

"Of course." was the answer and with that the tall blonde walked out as well.

Hanji heard a soft hissing noise and saw Eren's face and body steaming, his wounds slowly starting to close. "He truly is amazing. But I still have to apply bandages, or he could get infected with something..."

By the time Levi returned, Eren was wrapped in clean bandages, laying inside a tank barely big enough for the mermaid. He sat down cross-legged in front of the brunette and at first reached out to softly caress his hair, but stopped himself midway.

"It's alright, Levi. We will get him to New York in an hour, okay?" Hanji tried to cheer him up a little.

"What exactly is alright, shitty glasses? I ripped his fucking face off..."

"I'm sure he'll be fine, he's a tough little mermaid, remember?" Hanji said with a smile, grabbing Levi's hand and guiding it into Eren's soft brown hair. "We can apologize when he wakes up."

The rest of the time in the room as well as the flight back were extremely silent. Even the scientist didn't dare to make conversation, seeing how Levi was on edge. The brunette send the man home while they wanted to check on Eren in their own lab, and Erwin retreated into his office.

Hanji got the tank placed in her lab and opened it before pulling the mermaid halfway out carefully. The scientist gently pulled at the wet bandages to look at the wounds, only to find that they had mostly healed during the flight.

"The flesh pieces vanished and the raw flesh already has a thin layer of skin grown on top of it. His body is so interesting!" they exclaimed with euphoria and searched in the messy room for clean needles, as well as a medical thermometer and other devices to check the mermaid's vitals.

After the first test, Hanji ran to the phone on their desk. "Hello there! Yes, of course it's me, and I told you, Hanji is fine! Anyways, I have something really interesting in my lab, maybe you want to check it out~? You'd be one of the first humans to- yes. Yes, I just need someone to write my reports... Really?! Thank you so much!"

It took only a few minutes before a young man with short brown hair entered the lab. "Dr. Zoe, please. I'm still working on your last reports about the- is this the deep sea mermaid?"

"Moblit, perfect timing!" Hanji sprung up from their spot and ran over. "Moblit, meet Eren. Eren, meet Moblit when you're awake. Anyways, I'm checking on his vitals right now and need you write it down. The first thing would be, even though he appears cold on the outside, his inner temperature is really high! Extremely higher than other mermaids, which are a bit colder than us humans, but even for a human he's hot! Can you believe it, he lives on the bottom of the ocean, but despite it being there only a few celsius, he's running on 39 degrees! A human would-"

"Could be in hospital with a fever, I know." Moblit sighed, and got a empty stack of paper from Hanji's desk. "What else?"

Hanji's eyes lit up. "Okay, let's see. His blood pressure is 95/65 mm Hg. Mostly normal, if not even a little low. That's surprising... But, that might be helpful in deeper ocean levels. Hey, did you know th-"

"Dr. Zoe, let us finish before he wakes up and gets uncomfortable with us poking at him."

Hanji began to pout, but listened to their assistant. "Alright, alright. Next up, I already drew a bit of blood, it looks a bit darker and thicker than normal mermaid blood, it resembles more human blood. I guess his healing ablilities are partly coming from that fact. And his heart rate... woah!"

Moblit sat up straighter instantly. "What is it?"

"I checked his heart rate on the island, his heart was beating faster than a mermaid's or humans, and not thanks to stress. But right now, as he's sleeping... it makes me question if we can even call it sleep anymore!"

The man hummed and leaned closer to the tank. "What would you call it instead?"

Hanji slowly turned to their assistant with a serious expression. "Hibernation? Slow breathing and heart rate are symptoms of hibernation. Maybe even this temperature is low for him, and it would make sense why Eren doesn't wake up."

Moblit stood up and kneeled next to the scientist. "So what you're suggesting is, he felt threatened and stressed from the researchers in Washington and decided to shut off completely? But going into hibernation wouldn't be exactly an instinct to protect his body, except..."

Hanji nodded. "Except he did it to protect his mind. Eren has amazing healing abilities, so he probably didn't worry about wounds they could inflict, even if it's slowes down a bit with a slower heart rate. He probably panicked, took flight into the corner we found him in and in order to remain in his spot, without the need for food and to not have to experience what they did to him, went into hibernation. It's kind of smart if you think about it like that."

"But isn't it weird?"

Hanji tilted their head. "What?"

"Hibernation." Moblit deadpanned. "Deeper levels of the ocean aren't affected by the temperature changes on the surface. Eren has no reason to hibernate during winter."

"Oh my, of course! You're right! Eren has no reason for hibernation during winter or for aestivation in summer! He has no reason to go into torpor in general since there should always be enough prey to catch in deeper ocean levels and I can't think of something else..."

The assistant hummed in thought. "You said he's over 2500 years old. Maybe he can sleep for a long time, similiar to something like torpor?"

"It's possible, but we don't know for sure, we'd have to ask him personally when he wakes up. The problem is, if you're right, he could sleep until I have grandchildren researching in my place! And poor Levi, of course... I can't even imagine telling him, the look on his face and-"

"Dr. Zo- Hanji, calm down. I think Eren knows that he can't oversleep." Moblit said in a gentle tone, rubbing his hand over Hanji's back comfortingly.

"Yeah... Come on, let's continue." With a heavy sigh, Hanji asked Moblit for a scalpel and cut off a small piece of Eren's skin from the hand, as well as carefully extracted a loose scale near a bigger wound.

"Let's go test this. I'll go ahead and you call Erwin, he shall send someone with a baby phone and camera, I want to know it in case he wakes up, he's been scared enough, he doesn't need to have a panic attack in my lab, too."

Moblit nodded, understanding, and pulled Hanji into a small hug before they left. "Don't worry, it will all work out. And maybe it's for the best if we don't tell Levi yet. But if you want, I can call him to say Eren's body is healing good and that he's sleeping."

Hanji smiled and patted their assistant's shoulder. "That's a brilliant idea, Moblit! Thanks!" they said before rushing to the other room.

The man sighed and used the phone on Hanji's desk to call the raven.

_"What do you want, shitty glasses?"_

"This is Moblit Berner speaking, sir. I'm calling to inform you that Eren's wounds are healing unexpectedly fast and well, he will be as good as new soon."

A heavy sigh of relief could be heard from Levi's end. _"Thank god. So, how's Eren doing? Did he wake up yet?"_

"I, uh, just joined Dr. Zoe in their lab. Dr. Zoe is off to test Eren's blood right now, so I don't really know for sure. Right now he's sleeping, though."

_"....Alright. Please try to stop the shitty glasses from doing too wierd experiments, got it?"_

Moblit smiled at that, even though Levi couldn't see it. "Of course."


	13. Awakening

Eren woke up slowly, feeling heavy and only wanting to keep his eyes closed and fall right back asleep. That is until he realized he wasn't in his safe, fleshy cocoon anymore.

 

His eyes snapped open and he looked around, panic rising as he saw he was still in some kind of room like before, with an artificial light burning in one eye, while the other wasn't seeing anything. A moment after the other sensations bled through. The weird, stinging scent, the sound of machines and... breathing? But it wasn't his own.

 

The mermaid looked down to see he was in a small tank, with his head outside the water, resting on the glass wall. Eren carefully turned around, his limbs aching from not moving for a long time, and saw a man sleeping on a chair, the head on a messy desk.

 

Eren thought about his possibilities and decided to carefully call out to the human, hoping that it wasn't someone bad, who wanted to harm him, but the man didn't look too dangerous. The mermaid knew in the back of his mind, that often kind looking humans could be crueler than the dangerous looking, what a weird species they could be...

 

The man jumped a little in his seat and then turned to look at Eren with wide eyes when the mermaid made a small sound.

 

"Oh, hello there." he said smiling.

 

Eren smiled back a little, still wary and nervous being in disadvantage and defenseless.

 

"Hey, you have no reason to be scared anymore, it's alright. You're safe here. Let me call Dr. Zoe to inform them you're awake, okay?" Moblit said before standing up and opening the door. "Dr. Zoe! Eren's awake!"

 

Eren tried to make himself smaller as he heard steps coming closer, running.

 

"EREN!" Hanji screamed excitedly and rushed to the tank to pull Eren into a hug that was immediately returned.

 

"Hanji!! ...Where Levi?"

 

"Levi will be here soon." Hanji answered smiling and motioned Moblit to go out and call Levi in the hallway to come over.

 

"Good." Eren grinned and began to pull at his bandages that were blocking one of his eyes and covering his body.

 

Hanji reacted quickly, putting their hands on top of Eren's to stop him. "Eren, honey, no. It could become infected."

 

The mermaid frowned a little and tried to turn in his small tank. "Hanji, it hurt."

 

The scientist smiled in sympathy, helping to Eren to turn. "I'm sorry, Eren. I know the tank is way too small, I'll try to organize something bigger until we can get you to the ocean, alright?"

 

Eren giggled a little. "Hanji, you say too many."

 

Moblit walked back over Hanji, who grabbed him by the collar and pulled him down. "Isn't he just the cutest lil' thing?! No wonder why Levi fell for him! Come on, say hello!"

 

The man huffed out a smile. "Good morning, Eren. I'm Moblit."

 

"Hello, Moblit. I'm Eren!" The mermaid smiled and waved.

 

"He really is precious. You sure he's several thousands of years old?" Moblit chuckled. "By the way, Levi's coming together with Erwin in about half an hour."

 

"Levi? What have you say, Levi?" Eren asked curiously.

 

Hanji smiled and took her watch off, giving it Eren. Then they pointed at it and made a line, indicating half an hour. "When this is here, Levi will be here."

 

Eren copied her motion and repeated the end. "There. Levi here. Right?"

 

Hanji nodded with a big smile, ruffling the mermaid's hair. "Moblit, get me pen and paper." they waited until their assistant gave them the said things before drawing her measuring Eren's temperature, blood pressure, and heart rate. "Say, Eren, can I check your vitals?"

 

"Ähh... yes?" Eren answered hesitantly, looking closely at the drawing.

 

The scientist giggled in delight and ran around in the lab, gathering everything. "Okay, heart rate first, that's the least disturbing, I think." they muttered before carefully approaching the mermaid at the end of the stethoscope and placing the metal against his chest.

 

"Alright, Eren. Now breathe." they ordered, taking deep breaths for Eren to copy, which the mermaid did obediently. "Moblit, heart rate around 200. And yes, he's calm."

 

"Incredible. Guess the thick blood has to be pumped quickly to make his healing powers possible..."

 

Next, the scientist pulled the cuff for blood pressure on Eren's arm and secured it. While adding pressure, Hanji tried to calm the mermaid down before he could even begin panicking. "Okay. You're doing good, Eren. It's alright Eren."

 

"And?"

 

"The blood pressure would be normal for a human. It's the border to low pressure though, 90/60 mm Hg."

 

Lastly, Hanji removed the cuff again to place a thermometer in Eren's mouth. "Hold still for a second." They all waited for a minute, Eren slowly getting nervous what the scientist was doing to him and why, but trusted them to not hurt him.

 

Eren flinched when the metal in his mouth made a beeping noise, and almost swallowed it, but Hanji was quick enough to pull it out. "Let's see... 41?! A human could die if he'd have such a temperature!"

 

"I think that would be enough, Dr. Zoe, Eren looks a bit nervous."

 

The mermaid tilted his head at being called and reached for the man to come closer when Hanji nodded and went to the desk quietly. When Moblit squatted next to the tank, Eren pulled him down by the collar to whisper in his ear. "How you Hanji silent?"

 

The man began laughing and pulled away. "That's an art that comes with time. Levi hasn't mastered it, though. And he knows them longest!"

 

The scientist looked curious. "What's going on? What did he tell you?"

 

"You no hear." Eren laughed in a light manner.

 

"You witty little fish, you..." Hanji replied before clapping once. "Alright, now I'm bored! Anyone up for something to watch? I have a TV here!" they asked, but didn't wait for an answer, turning it on and began to turn Eren's tank so he could also see what was going on.

 

For the next minutes, they began watching King of the Hills, with Hanji laughing like crazy, while Moblit only chuckled and Eren mostly wondered how the pictures moved and could talk like humans. The mermaid decided that it was quite entertaining to see.

 

-~-

 

Levi was walking down the hallway as quickly as he could without actually running. He only got a call from Moblit saying that he should come to Hanji's lab immediately and hung up again. Apparently, he also called Erwin, since the tall blonde man was waiting for him in the parking lot.

 

"Levi, slow down a bit."

 

"Erwin, for fuck's sake, shut the hell up. I have no idea what happened to my Eren. For all I know, he could be dead!"

 

" _Your_ Eren?" Erwin asked amused, trying to distract Levi a bit.

 

"Yes, _my_ Eren. And he's _only mine_ , so fuck off." the raven hissed and finally reached the door. He opened it to see the TV on with Hanji and Moblit laughing and Eren leaning on his arms on the side of the tank.

 

"Eren..." Levi whispered, but Eren heard him nevertheless and turned around, smiling happily. "Good morning, Levi! Good morning, brēwō."

 

Erwin raised an eyebrow at that. "Brēwō? What's that?"

 

Hanji looked at Eren curiously before digging through several book piles.

 

"Anyways, good morning to you too, Eren. My name is Erwin Smith, but just Erwin is alright."

 

Eren smiled and nodded, then leaned back to open his arms wide, and Levi instantly ran up to him to pull the mermaid into a tight hug. "I missed you so damn much."

 

The brunette giggled and hugged Levi back. "I love you, kleini."

 

"I love you too, brat." Levi sighed and pulled back a little to look at his mate. "I'm sorry I hurt you..."

 

Eren tilted his head in confusion. "You hurt I?"

 

The raven nodded and gently tapped at Eren's neck and made a cutting motion. The mermaid thought about it for a second before smiling at Levi warmly. "It good, Levi. I good."

 

Levi shook his head. "You aren't good. You're covered in bandages for crying out loud!" he said and pointed at the bandages wrapped around Eren's head and eye.

 

"I good, aba Hanji say no."

 

Hanji looked up from their book at that and walked closer. "Really? Then let's see."

 

The scientist carefully pulled at the bandages and rolled them back up to reveal a perfectly fine Eren.

 

"You see? I good." he repeated, reached up to ruffle Levi's hair. "No cry, Levi."

 

Levi frowned and leaned in closer. "Did you fall on your head or something? I am  _not_  crying."

 

The mermaid smiled knowingly and pointed at Levi's chest. "You cry here."

 

Levi resisted the strong urge to start a full blown-out make out session in front of Hanji, their assistant and especially Erwin.

**Notes for the Chapter:**

> New Chapter today served extra long and fluffy after all the shit that went down.   
> (The meaning of Erwin's nickname will be reavealed soon as well) ;D


	14. Lightening Things Up

"Oh my god!" Hanji suddenly began laughing.

Levi turned his head to glare at them. "What is it, shitty glasses?"

"Eren, forget Erwin. His name is not Erwin anymore. His name is brēwō, okay?" they giggled, and Eren started to join, nodding.

"I know." the mermaid laughed.

"Levi, come here for a second." Hanji waved the raven over to them, together with a curious Moblit. "I found this dictionary of the Indo-European language a while ago. Look at this!"

Moblit was the first one to spot the word brēwō with the english translation: Eyebrows. Levi read it soon after and they both shared an amused look.

"The brat has the best humor sometimes. Erwin's name is officially brēwō now."

Before Erwin could intervene, was Hanji standing up and walked over with the book. "Eren, I have a question."

"Yes?" The mermaid asked, a little confused.

Hanji picked up the pen and paper next to the tank and drew a picture of a sleeping mermaid. "You were not sleeping back then. What were you doing?"

Levi turned to give the scientist a harsh stare. "What do you mean, _not_ sleeping?"

-~-

After a few explanations, the rest of the group was updated about Eren's body in the last weeks and Eren struggled to explain, but eventually managed it, with Hanji translating, to say that his species can go into Torpor in case another mermaid wants to eat them and they have to hide for a while, same goes for the crystal form.

"Wait. You eat each other just like that, too? Not only mates? I thought it was like spiders, female eats male for the kids." Levi frowned.

Eren nodded at the first part and looked down, motioning Levi closer to whisper something.

Levi's expression softened and he looked at the other 3 people in the lab. "Could you leave the room for a moment? We'd like a moment for us..."

"We'll go to the cafeteria for some coffee and breakfast, then. "Erwin said and Moblit nodded, pulling Hanji along.

Eren sighed when they left. "Levi... I have to say thing." his look saddened and tears began to form. Levi felt his heart tighten at the sight.

"Deep sea mermaid monster. Titan monster. Titan... t-titan e-e-eat  my... my m-moth-ther..." Eren began sobbing at the end.

The raven pulled Eren closer, leaned the brunette's head on his shoulder and soothingly ran his hands down the back.

"F-father think I... w-we no many food... h-he think I e-eat m-mother. He... he want eat m-me, I... Levi, I eat f-father... I monster. They monster, I monster! L-Levi, I monster!" Eren cried out loud, hiding his face in Levi's shoulder.

Levi didn't know how to react at that. He was always confused and complete shit at comforting people, but how do you comfort someone who had to eat his father for survival and thinks of himself as a mindless beast? The human continued to stroke Eren's back and moved his other hand into the mermaid's hair.

"Eren... don't cry... It's alright, you aren't a monster."

The mermaid shook his head. "I hurt other... I monster. Ik dula nixa..."  
(I'm a dumb monster)

"Eren, look at me." Levi said, pulling the brunette from his shoulder to look into the pools of teal that were Eren's eyes. "I killed people in my past too. If you think you are a monster because you hurt someone, then I'm a monster too."

Eren's eyes widened, his tears falling faster. The mermaid pushed his body forward to press his lips against Levi's and slung his arms tightly around his shoulders.

They stayed for a few minutes just like that, clinging to each other with an occasional, loving kiss, neither of them saying anything. Eren was the first one to break the silence.

"Thanks, Levi."

"No problem, brat," Levi responded with a slight smirk, making Eren smile again. "Was Washington scary?"

The mermaid nodded. "Yes." He pointed at the lights and his eyes. "Hurt." Then he made a whirring sound like the one he heard in the tank. "Scary many..."

"I'm sorry, Eren. Really. You shouldn't have to go through that."

"No, Levi. I sleep, I no hurt. I good." Eren smiled gently, giving Levi's forehead a soft kiss, causing the raven to blush a little.

Without warning, the door opened to reveal an excited Hanji. "Eren, what would you say if I get you to my home first? It might take a while before Levi's house by the ocean will be planned and built, and this tank is probably way too small-"

"Hanji, too many words. Eren, you want to go to Hanji's home? They have a big swimming pool."

"What that?" Eren asked, tilting his head.

Hanji grinned and picked up pen and paper to draw her pool. "It's full of water, and outside. No walls or anything!"

Eren's eyes lit up. "Good. Yes. Aba, Levi there."

"As if I'd leave you alone with crazy." Levi snorted.

The mermaid tilted his head in confusion to the other side. "What crazy?"

Levi waved his hand in front of his face and then pointed at Hanji.

"Ah, dula! Dula Hanji!" Eren said and began to laugh.

Hanji giggled and walked over to her desk to flip through the pages of the dictionary. "Eren, þu blȩsti, Ik nur knap!"  
(Eren, you're talking nonsense, I'm just clever, that's all!)

Eren smiled in relief that he didn't need to struggle with translations and laughed softly. "Bidjan, homo. Witan þu oord." he said in a light, mocking tone.  
(Please, human. Know your place.)

Hanji looked it up and grinned wide. "Levi, I think I'm going to buy you a dictionary, too. Learning english is definitely limiting the boy!"

Levi shook his head at that. "No."

"...No? But don't you wa-"

Levi stood up and interrupted Hanji by taking the book. "You're going to buy _yourself_ a dictionary."

"Whaaaat?! But Levi, I have important studies to do and research deep sea mermaids! So far I could only check his vitals an-"

"I don't give a flying shit, Hanji. Also, if Eren's going to live in your pool, then I'll be staying in your guest room for a while."

"Alright, you don't have to pay rent and can stay if you do the work around the house!" Hanji said excitedly, looking forward to not doing dishes for a while.

"You can't clean properly anyways, I would have to do it either way, so okay. I guess."

Hanji jumped up and down in her euphoria. "Yay!"

Eren smiled contently at the scene. Finally, he was home. Maybe not in the ocean, or near the place he was born and raised, not even in a tank that fit him, but he was with Hanji and his mate Levi. And that alone made the mermaid incredibly happy.

**Notes for the Chapter:**

> Work shifts, timezones, who the hell cares about update times anymore? ;)
> 
> (Today it's early, next one at some point on sunday :D )


	15. Meet your new neighbor

**Notes for the Chapter:**

> Don't be confused with the chapter update time, AO3 messed it up and I have no idea what's happening :D

Thankfully, it didn't take long to organize the short trip to Hanji's home and soon Eren found himself being in a big pool. It would be a tight fit in his bigger form, but as a small mermaid, it was enough and definitely better than the tiny tank before.

"Thanks, Hanji!" he said happily and swam a few rounds to move his muscles again after the last days of barely moving at all.

"It's no problem!" Hanji called out from where they were standing on the edge of their pool. "We will get Levi's stuff inside and then come back again, okay?"

"Okay!"

Levi hurried to get all his bags inside and make himself comfortable in the guestroom. "Shitty glasses, we have to clean this dump immediately, your house is worse than I thought."

-~-

While the two humans were cleaning the house spotless, was Eren still swimming his rounds until he heard a rustling noise nearby and looked around.

A child appeared next to the pool with a wide smile when it saw Eren. "Fishy!"

Eren tilted his head, confused why there was a child and wondered if Hanji had children but never mentioned it.

The boy held out his hand towards the mermaid and Eren carefully swam closer.

"Hello, what you name kindi?" Eren asked, smiling back.

"You talk funny!" the boy laughed. "I'm Eric. Can I pet your tail?"

Eren pointed at himself. "Eren"

Then, he swam to the edge and pulled his upper body onto the pool edge, being supported by his arms.

The boy pouted that his request wasn't fulfilled and got closer to reach out and grab a part of Eren's tail, causing to mermaid to gasp in surprise.

"Eww, so slimy!" the child complained and wiped his hand on Eren's arm.

"S-Slimy?" the mermaid asked, yelping when the child pulled his hair.

"You're so stupid!" the little boy chuckled. "A stupid, stupid stuuupiiiid fishy!"

Eren pulled away and growled. "Hōra-uχ þu kleini... habēn þu keen árnja?!"  
(Listen here you little... don't you have any manners?!")

Eric flinched, tears beginning to form in his eyes. "Waaaaaaa!" and with that, he began crying and ran out of Hanji's garden, through bushes to the next house.

The mermaid sighed, rubbing over the spot where the child had pulled harshly on his hair. And just when he hoped he was done dealing with the little brat, Eric returned with a bottle in his hand, still crying.

"Y-You're a bad fishy, and wh-when I am bad and say mean things my m-mommy washes my mouth with soap!"

Eren only caught the words 'you', 'bad', 'say' and 'mommy' and barely had time to wonder how Eric's mother could judge his choice of words before the child splashed the liquid content of the bottle in his face.

The mermaid flinched, closing his eyes and mouth tightly afterwards and quickly wiped it away with his hands. The smell of it was horrible, even worse than the smells of the lab in Washington and Eren was sure if he had eaten anything, then it wouldn't be in him anymore.

He gagged and pulled a face, ducking his face underwater multiple times in an attempt to wash it off.

"There, now you will be nice!" The little boy grinned.

"þu blauþu-uχ balwa kleini beost!" Eren growled with a glare that could almost freeze the blood in the child's veins.  
(You stupid, evil little beast!)

Eric shrieked loudly, clutching the bottle close to him, too scared to move.

 _"SNAKAN!"_ Eren screamed in a dangerous tone, causing the little boy to run off again, with a growing wet spot in his pants.  
(SHUT IT!/FUCK OFF!)

-~-

Levi heard a loud cry outside, followed by a scream that could only be described as truly terrifying. He dropped the mop in his hands and ran outside towards the pool.

"Eren!"

The mermaid turned around with a look of pure anger and hate, that softened a little when he saw his mate.

Hanji followed a second after and joined Levi to the edge of the pool. "Eren, what happened?" they said worriedly.

"Eric." Eren spat out in hate. "Eric bad. Much bad."

"Eric?" Levi asked confused, while Hanji hummed and grabbed their head.

"That's the child of my neighbors. He's what you would perfectly describe as a little shit, Levi. His mother tries to teach him some manners with the result of him mirroring her actions. He hit me once when I wouldn't give him the chocolate I had." Hanji sighed.

"So it wouldn't surprise me if our little Eren got pissed off by him." they said and turned to Eren. "What did Eric do?"

Eren's face briefly flashed a look of murder as he gestured to grab his tail, pull his hair and splash water on his face.

The raven groaned, shaking his head. "Alright. He's a little shit. Hanji, are his parents at home?"

"They'll come home by seven, for now it's only the babysitter." Hanji giggled. "Try not to kill them!"

Eren whined a little and ducked underwater, swimming around before returning to the humans, only to repeat the cycle over and over.

"Eren? You okay?" Levi asked with concern when Eren went up again, leaning closer to the edge of the water.

Eren nodded. "Bad." he said and pointed at his nose, making a face before making another round.

"Hanji?" Levi asked the scientist for some kind of explaination.

"I don't know, maybe it's the smell of humans and city? I mean the filter works without any chemicals, and I even manipulated the water with sea salt so there shouldn't be a problem with the pool at all."

"I guess it doesn't smell here like in the wilderness..." Levi agreed. "I can only hope that Eren feels better in the actual ocean, but it's still near the city."

Hanji nodded. "We'll have to wait and see."

-~-

In the evening, Levi went over to the neighbors when he was sure they were at home. He politely rang the bell and knocked a few times.

A thin, but not fragile woman opened the door, dressed in a business like shirt and skirt. "Can I help you?"

Levi nodded. "Yes. You see, Dr. Zoe has me and another colleague over for a while. We would appreciate it if your son wouldn't try to hurt my co-worker anymore."

A woman brought her hand to her mouth. "Oh, I am so sorry about that. He won't just get away with such actions, I promise. May I ask what Eric did?"

"He was grabbing his tail without asking, pulled his hair and apparently splashed water on his face. It wasn't really any harm done, but it would still be better if he stops, of course."

"Oh, your colleague is a mermaid? What kind?"

Levi nodded. "It's an ocean type, staying in the pool outside. So please consider that he is already stressed enough."

The woman sighed in understanding and flashed a smile. "Alright. I will try to get some sense into him and if you don't mind come over tomorrow to apologize personally."

**Notes for the Chapter:**

> In case you're wondering, Eric is around five years old.


	16. They didn't change

**Notes for the Chapter:**

> Get yourself a nice chapter of fish drama :D

The next day, Levi went outside early with a fresh plate of raw fish Hanji had bought the day before they moved.

"Eren, I got you some food!" he called out over the pool. He stepped closer to see a big lump of raw flesh on the ground, with Eren slowly emerging from it like it was a cave.

The flesh disappeared within seconds after Eren broke through the surface. "No hungry."

Levi's expression softened. "Eren, you have to eat."

The mermaid only shook his head in return. "No. Bad." he pointed at his nose.

"The fish is fresh and you'll eventually have to get used to the smell of humans." Levi insisted.

Eren whined and reluctantly took the fish, swallowing them whole. Levi gently stroked through the brunette's hair in praise. He leaned in to kiss his mate, but Eren suddenly pulled away and turned his head next to Levi before throwing up.

"Ah, shit!" Levi cursed, rubbing Eren's back as he emptied his stomach next to the raven, the fish barely digested. "Eren, are you okay?!"

The mermaid let out a long drawn whine after wiping his mouth and laid his head on Levi's lap. "No. Bad..."

 _'The smell of humans and city couldn't cause such an intense reaction...'_ Levi thought and bend down to sniff Eren in attempt to know what smell was bothering him. And to his surprise, he smelled something familiar. Cleaning utensil familiar.

"Fuck, don't tell me-" he cursed and got up, gently putting Eren's head on the edge of the pool. "HANJI!" he shouted, and a few seconds later the scientist appeared.

"What is- oh my... was the fish bad?!"

"Clean this up, shitty glasses. And run check-ups on Eren. He smells like... drain cleaner or something."

Hanji nodded and right after they both cleaned the spot with water, Eric appeared with his mother, who looked panicked.

"Dr. Zoe, I am so sorry for my son."

Hanji stood up and walked over, crossing their arms.

The woman put her hand to her chest, trying to comfort herself. "I don't know how my son exactly got his finger on it, but he just confessed to me that he apparently splashed drain cleaner on the mermaid's face to... clean them? I am honestly so sorry, so is my son, he didn't know-"

Hanji interrupted her with raising her hand. "I see. Don't worry, I won't call the police, it was an accident. But, it was an accident with consequences. Eren seems to have taken serious damage and no matter how many apologies or anything, I would like it if your family would stay away from my pool. My property in general."

The woman nodded defeatedly. "Thank you. Tell Eren our apologies and wishes for getting better soon a-"

She got interrupted by Eren screaming.

The mermaid aggressively rubbed at his face before screaming and then tearing with his teeth into the flesh of his hand. Levi facepalmed in response when a seconds after the large deep sea form filled out the entire pool, with even the upper half his body leaning on the grass.

The woman gaped at the sight while her son shouted in fear. "Mommy, a monster!"

Eren roared and clawed at Hanji's garden, pushing himself closer to the neighbors.

"Please, calm down. Eren isn't dangerous, he only looks like that. It's like in beauty and the beast!" Hanji laughed, turned to the mother with the son.

Levi nodded in agreement, and the woman shook her head before heading back to her home with her child.

"Call Erwin, he'll know what to say in a situation like this..." the raven sighed.

Hanji rushed into the house to get her phone and Levi tried his best to calm his mate down.

"Eren, it's okay. We'll clean you in shitty glasses' tub and take care of the pool, then everything will be okay. Eren, listen to me. It's fine." Levi said, his worry growing as Eren continued to roar and clawed his way out of the pool until his whole body was on the grass and then began to drag himself towards the street.

"EREN! No!" The shorter male shouted.

The mermaid growled in a low tone, glaring at Levi like an actually dangerous, and ready to devour everything living, being.

"Eren! Stop acting like a damn monster and get back here for fuck's sake!"

The brunette turned around the same time Hanji returned with a patient stretcher and when Eren snapped forwards they were quick on their feet to stuff it in the mermaid's mouth instead of Levi.

Eren broke the stretcher into pieces with his powerful jaw and blinked confused, then roared again.

Levi pushed Hanji behind him for protection, but Eren didn't attack again, he started steaming and emerged from the giant body, flopping onto the grass.

"Eren. What the fuck. Seriously." Levi stared down at him, showing his emotions with his intense glare.

The mermaid pressed his head against the ground, shaking his head. "No, I Levi mate, I want Levi, Levi, Levi, Levi, Levi, Levi..."

The human's scolding look disappeared and he dropped to the ground as well, gathering Eren in his arms. "I got you, it's alright. Eren..." he said his mate's name over and over, hugging him to his chest and petting his head.

Eren thankfully calmed down and let himself be carried into Hanji's bathtub. And while they went to fix the pool water, Levi stayed to hold his hand.

"Are you okay now?"

Eren nodded silently.

"Eren, what happened?"

The mermaid wiped away forming tears. "I... I feel bad, when I big no wounds. I no monster... I angry, I no monster. Sorry..."

"So... you thought you'd heal if you transform and flipped out when the little shit called you a monster?"

"Kindi say monster. All say monster. You say monster. I no monster, you say before..."

Levi sighed heavily. "I'm sorry Eren. I shouldn't have called you that earlier as well, I know you don't like it. I just thought you would notice me like that. Why were you trying to leave though?" he asked and motioned Eren leaving the pool and garden.

"I want home. Ocean." Eren answered quietly. "You angry?"

"Of course not. I'm sorry that brat was such a piece of shit. The asshats in Washington, too. Not all humans are mean, Eren. Okay?" Levi shushed the brunette. He pulled him against his chest and Eren instantly wrapped his arms around him.

"I know. Human no change." he smiled against Levi's body. "When we go ocean?"

"Do you want to go now or can you hold on in the pool for another while? It's all up to you."

Eren hummed in thought. Then he pulled back a bit and licked over Levi's necklace. "Book and Paper?"

The raven understood and waited for Eren to pull back completely before getting up to bring his mate the dictionary with pen and paper as well. He gave Eren the things and waited nearby until he held out a sheet for him.

_'I know we were separate before short time, but I want a thing. Can we meet at your ocean after time, in II weeks maybe? You build house, I get thing.'_

Levi read the note with a raised eyebrow. What would a mermaid have to go and get? And after all they went through after leaving where they met, he wanted to leave him?

"Is it important?"

Eren flipped through the pages to find the translation and then nodded. "Yes."

Levi sighed, knowing he couldn't deny Eren whatever it might be. "I swear if anything happens, I'll kill everyone on this fucking piece of earth."


	17. Another small journey

Erwin visited soon after, first handling the situation with the horrified neighbors and then came over to Hanji's place.

"Brēwō!" Eren grinned when the tall man entered the bathroom.

"Hello, Eren. Dr. Zoe told me everything. Are you alright?"

The mermaid nodded with a warm smile. "Yes, thank you."

"Anything else, eyebrows?"

Erwin smiled at the nickname. "Not really. Will Eren be okay with staying in that pool for weeks?"

Levi brought his hand up to press his face against the palm. "No, he wants to go to the ocean and meet again when the house and shit would be done."

"I can understand that. But I would worry more about you. To be honest, you don't do well with Eren away from you for too long."

Levi shrugged in an indifferent way, even if the taller man knew what was behind it.

"What if he stays near the shore and you visit often?"

The raven gave Erwin the note before rushing out of the room, cursing under his breath about never getting to spend time with his mermaid. Erwin read the note and then squatted down next to the tub to be with Eren at the same eye level.

"How about you get the thing quickly and then we'll work something out, hm? If you don't like pools anymore, you could stay in the ocean near Levi. Maybe you can even help with the house?"

"Yes." Eren nodded with a soft smile. "I want near my Levi be!"

-~-

After most of the day spent in the tub alone after Erwin left, Eren crystallized and the humans transported him to the ocean.

"Couldn't you at least have said _anything_ , Levi?" Erwin asked in the car.

"I will when we arrive. Now stop bothering me, both of you asshats, I want to sleep."

"You never sleep, Levi." Hanji huffed but complied and a silence spread out for the rest of the drive. Eventually, they reached the ocean and gently put Eren down in the shallow water. The mermaid let his shell dissolve and looked up at the humans happily.

"Thank you!" Eren said, flapping his tail excitedly so that it splashed ocean water everywhere. "Bye Brēwō, bye Hanji!"

Eren bowed heads with Erwin and hugged Hanji as a goodbye, waiting until they went back to the car, leaving the two lovers alone. Levi sat down next to his mate and gestured Eren to come over.

The mermaid smiled as he leaned against Levi. "Levi?"

"What is it, brat?"

"I swim there and home fine. You here fine. Okay?"

Levi put his arms around Eren and kissed the top of his head. "Of course I'll be fine. I even have something for you." The raven pulled a pair of small earrings out of his pocket. "I bought this when you were in Washington... I thought you'd like something back in return for the necklace you made me."

Eren turned around and his eyes lit up at the sight of the earrings with a stripe of turquoise braided together with the two main made out of gold. "Gulþa...?"

Then, to Levi's surprise, tears formed in Eren's eyes, but it showed that they weren't out of joy.

"Levi... You... You many gulþa?"

Levi blinked a few times before placing his hands on each side of Eren's face, wiping away the tears with his thumbs the same time he spoke. "No, gold is rather expensive."

Eren smiled at that and leaned in to kiss his mate before he sighed in relief. "Good."

Levi smiled into the kiss as well, then put his hands to work to put the earrings on Eren. He hummed in praise when the mermaid barely moved from the pinch of his ears getting pierced.

He pulled away first, to admire his work properly and Eren brought his hands up to feel his new accessories.

"Thanks... I love you, Levi." Eren said softly while grinning. "You good mate!"

The raven started blushing a little. "I love you too, brat."

"Kleini," Eren responded with a playful roll of the eyes. "When I home, Levi, I, mate," he smirked.

"Why not now?" Levi asked.

"No this." Eren shook his head. "You english, I necklace then Levi, I, maybe mate. You gul-äh-gold, I... I something too. Then Levi, I, mate. Forever."

Levi hummed in understanding. "I see. You guys charm each other with gifts..."

The mermaid tackled the human to the ground and hugged him tightly. After a minute, he felt his tail dry out in the evening sun and crawled more into the water, having to let go of his mate.

"You no cry, Levi. I fine. When I back I fine, Levi."

Levi nodded. "I'll trust you. The ocean is your home after all..."

"No."

The human raised an eyebrow in surprise. "What?"

"Ocean no home. Levi my home." Eren smiled happily and reached out for Levi to come over and kiss him goodbye.

Then, he bit into his hand and gave Levi a low growl before disappearing into the depths of the ocean, leaving Levi to stand there on the beach alone.

_'He's too cute... I'm his home!'_

Levi smiled the whole drive back and couldn't wait to help to build their house. He wanted only the best for his mermaid after all.

-~-

Levi sat on Hanji's couch a few hours later, a glass of wine in hand.

"How the fuck will I know when Eren returns? It was a stupid idea to let him leave like that..."

Hanji hummed and rested their head on their hands. "I'll visit the beach before and after work, and if you want we could hire someone standing there like it's an airport with a sign reading 'EREN'." they giggled and took a sip of their own wine.

"Maybe, I'd blame myself without end if something happens... But you know what was weird? Eren cried when I gave him the earrings and asked if I had much gold at home. A bit like a dragon..."

Hanji raised an eyebrow in interest. "Oh? Interesting... Gold had a much higher value in the past, maybe it was for him like you dropped bags of diamonds on the beach like it was nothing? I'm much more curious about with what he'll come home, though! Eren sounded like he had something specific in mind..."

Levi twirled his glass in thought. "I'm just hoping it's nothing too weird."


	18. Key

Hanji was walking along the beach after work, just like they did the last 16 days. Levi was mostly focused on his house to distract him, but the scientist could feel him getting significantly more worried ever since the two weeks passed.

They stopped in their tracks when suddenly, a loud splashing sound reached their ears. Hanji looked out further across the ocean and saw Eren getting closer and dragging himself onto the sand in his deep sea form.

"Eren! You're back!" Hanji screamed excitedly and ran over.

The mermaid lifted one giant arm to wave at them before bending down, his face almost touching the sand next to the brunette.

Eren opened his mouth, and big wooden boxes fell out along with clutter covered in moss and seaweed. Hanji saw them spill out across the beach and wondered if the mermaid's mouth was even big enough to fit all of that inside. But soon the thought was pushed aside when they saw the symbol some of the boxes had.

"O-Oh my god.... Eren... This is incredible! I gotta call Levi, this is just truly amazing!"

The mermaid huffed short breaths in laughter and then dissolved his deep sea form. He climbed out of the nape of the neck and landed on the sand with a happy grin.

"Hanji!" he brought the attention back to him and reached out with one arm, which immediately had him a scientist almost hugging the life out of him.

"Oh, Eren. I missed you so much! And don't worry, I'll get Levi over as soon as possible. And apparently a few trucks." Hanji giggled and then pulled away enough to examine the mermaid.

"What's that around your neck? A key? And oh my, you got a bit thinner as well... You need to eat properly if you-"

At that point, Eren blended them out and took the key into his hand, playing with it in the last rays of sunlight.

The moment was interrupted when Hanji's phone rang and Eren flinched away before he could hear Levi's voice coming out of it and boldly ripped the phone out of Hanji's grip.

_"Shitty glasses, get your ass over already, I'm tired and it's your turn to cook. Hey, Hanji, are you even listening?"_

Eren grinned at the sound. "No Hanji. Eren!"

There was a thump heard on the other line before Levi spoke again. _"You're back! Hold on, I'm coming over-"_

"And call Erwin, we need at least one truck with several trailers!" Hanji intervened.

_"...what"_

"It's a surprise, just do it and hurry up!"

-~-

Levi arrived soon later, running towards the beach until he saw the boxes.

"What the fuck?"

Hanji giggled and called out to the raven. "Right?! And look at some of these boxes, doesn't the symbol seem familiar?"

Levi's jaw dropped a little and he nodded silently. "I know what a fucking swastika is, shitty glasses. But... is this for fucking real? Of all things, the brat comes home with a fucking nazi treasure?!"

Eren began pouting and flapped his tail against the water to get his mate's attention. "Kleini, say hello!"

Levi turned back around to the mermaid and closed the distance, dropping to his knees to pull Eren into a kiss.

When they eventually parted was Levi placing both hands on each side of Eren's face. "I'm sorry, Eren. I was just... very surprised, I guess."

Eren smiled and pulled Levi closer, resting his head on his mate's shoulder. "Is fine. Levi, I good mate? You gold, I gold."

Levi huffed a laugh. "Eren, I gave you two small earrings, they aren't even completely made out pure gold! And you got me some Nazi gold that could be worth... I don't even know..."

"Depending on the exact contents of these boxes, it could be worth millions, maybe even billions!" Hanji interrupted and wanted to continue, but then they saw the trucks and ran to Erwin and two other men to talk their ears off.

Levi turned Eren in his arms and sat fully down on the sand so that the mermaid was comfortably seated between his legs. "Is the key part of the treasure?"

Eren looked up in confusion until Levi touched the medal around his neck. "No. Father, Mother."

"Your parents gave you this?"

"Yes..." Eren sighed.

Levi hummed softly. "I'm curious, though. And we have some time until they loaded all the gold into the trucks, so tell me."

Eren hesitated, and his eyes glazed over when he started speaking in a shaky tone. "You... y-you know titan eat my mother. Titan, name Dina, first mate father, he ran before she eat father."

"Your father had a titan as a mate?" Levi asked in disbelief.

Eren nodded and continued his story. "My mother good, no eat father after mate, no eat me, no eat human. When I... you know. Father had this-" he paused to point at the key. "Mikasa, Armin help me. This Dina home. I see this, I know titans bad. Mother, I, good."

Levi pressed his lips onto the top of Eren's head for comfort. "So this key reminds you of being good... Why didn't you have this key before? And what happened to the titan?"

The mermaid smiled at the contact. "I no want Ymir eat... key? Mikasa kill Dina." Eren said with a proud smile.

The human hugged Eren closer, rubbing his cheek on his head. "I'm glad it ended well. I missed you, Eren. But you look a bit thinner, didn't you eat enough?"

Eren groaned and looked up with a pout that Levi could only describe as adorable. "One Hanji say this, two you say this. I fine!"

"I'll still fatten you up a bit, I could lift you with a finger right now, seriously..." Levi mused. "So, what now? You probably don't want to go back to Hanji's pool, and the house will still take a while..."

"I help house?"

The raven thought for a second. "If you really want to then of course, yeah. I guess you actually could help get things done faster if you're in your bigger form... How long can you stay outside the water?"

Eren just shrugged in response. "I no know. Aba, we go tomorrow. You tired."

"Can I stay here for tonight? We could catch some fish for dinner and even though I was kind of freaked out the last time, it was comfortable in your flesh tent..." Levi said while hugging him closer, his chin rubbing against Eren's head.

The mermaid gave a face-splitting smile at that and pushed himself out of Levi's grip and crawled back into the water. It barely took him a minute to come back with two big fish in his hands. After Levi had his cooked above a fire and Eren ate his fish raw, Eren dug a hole underwater and waved his mate over.

Levi hesitated but stepped towards the edge of the water, only to suddenly step on flesh instead of feeling water. He made his way into the hole and settled down next to Eren, who then smiled and closed it around them.

"You good?" Eren asked in the darkness.

"It's really weird, but I've never felt a bed better heated... or with someone better next to me." he blushed at the last part.

Eren giggled and pulled Levi closer with one arm, the two bodies tangling with each other.

A minute of comfortable silence passed before Levi spoke again. "What about air?"

"You fine, slēp." a low murmur returned, making Levi think about how exhausted his mate might be. He snuggled up even closer and buried his head in Eren's chest.

"Good night Eren, I love you." he smiled when his answer was a light snore.


	19. New Home

**Notes for the Chapter:**

> Short but sweet :D

Darkness.

That was the first thing that greeted Levi when he woke up. Then, he felt Eren's warm body pressed against his, causing him to smile in content. He wished he could lie there forever and cuddle, but his body had other plans.

"Eren." he said in a light tone, stroking the mermaid's hair.

"Nnngh..."

"Eren, get up, I have to piss." The human sighed, scratching behind Eren's ear, which earned him a small yelp.

The mermaid shot up to loom above the raven, eyes wide open and with their soft glow the only visible thing in the darkness. Slowly, the flesh moved around them to make an exit for Levi.

"Uhm, thanks." Levi rushed to say and climbed out. After a good minute, he returned to the spot to see Eren climbing out as well, the flesh dissolving into steam.

Eren rubbed over the part Levi scratched lightly with a small grimace.

"You okay? I didn't hurt you, did I?" Levi asked, dropping down next to him.

Eren shook his head, smiling at his mate. "No, aba feel... äh... tēsen."

Levi raised his eyebrow in confusion and carefully reached out with his hand. "Let me see for a second."

The mermaid complied, tilting his head and leaning towards Levi. The shorter man looked at the spot, seeing that the skin wasn't irritated and was actually perfectly fine. He lightly brushed over the spot again, gaining a low whine.

"Sensitive spot, huh? Did the scratch feel more good or bad?"

"G-Good?" Eren answered, his head dropping down into Levi's lap.

Levi smiled at that and began to softly stroke the skin behind Eren's ear, occasionally scratching along the hairline. The mermaid hummed contently, his tail flipping a little against the shore.

"It's like a dog wagging its tail..." Levi mused. "Cute."

They stayed like that for a few minutes until Levi retracted his hand, hearing a whine in return. "Let's go, you wanted to help around the house, right?"

Eren nodded drowsily, grabbed a hold of Levi's hand and tugged it towards the ocean.

"Levi, water?"

Levi stared blankly. "You... you want to swim with me there? Am I riding on your back again?"

Eren nodded. "I small? You want go water?"

"Oh. Fuck it, why not. It's warm enough for a swim and if you promise to not let me drown I'll be fine."

The mermaid grinned happily and barely waited for Levi to take off his shirt and pants before dragging him into the water. He held the raven tightly around the waist and kept them floating.

"Good?"

Levi gave a small nod, then hugged Eren tightly as his mate lazily swam in the ocean, following Levi's directions.

"This feels really nice..." Levi thought out loud hallways. "We have to go swimming more often. If the waves go wild we could even go surfing, I wonder if mermaids can do that..."

Eren giggled. "Levi, you talk much again."

The raven pouted at that but didn't object much. "I missed you, okay? I'm just happy we're both safe and sound."

"I no understand much, aba I happy."

-~-

After a while, they arrived at the site. Eren helped Levi get onto the beach and looked around excitedly while Levi got dressed again and then went to talk with the workers.

Levi returned shortly after with a clipboard and a pen. "Alright, this is how it's supposed to look like in the end," he explained as he showed Eren the plans.

"You could first help with the underwater fundament, the glass is ready but it's difficult to set it into the ocean."

Eren nodded in understanding, then made a pose to show his muscles. "I help much!"

Levi chuckled and watched how Eren turned into his deep sea form, startling the other workers.

"Okay, listen here. This is Eren. Talk loud and slowly while giving instructions, his english isn't the best."

The workers nodded and went back to their work, only a few joining Levi to tell Eren what to do. The mermaid roared a little and only a few hours later he was done with the underwater fundament.

Then, Eren crawled on land and helped with the steel and wall plates to construct the robust structure. By the end of the day, the fundament and walls of all stories had been finished except the concrete filling.

Hanji arrived soon later with meals for them and Eren changed back into his smaller form, cuddling with Levi as they shared their food.

"This already looks amazing! So tell me, what are the exact plans?"

Levi turned to Hanji with a proud smirk. "Well, the building consists of two stories above water and two underwater. The fundament is mostly on land, but a bit stretches out into the water. There will be two main entrances, one underwater on the ground and one normal door on land. So Eren can easily enter and leave the house. The lowest floor is below the ground, where the water entry is located by the ocean floor, but Eren can swim up through a hole into the second floor with a smooth ground right under the house floor. The walls underwater are completely made out of glass, if you don't count the filters in."

Hanji's jaw dropped in awe. "That sounds amazing! So Eren has his home underwater and yours is on top of it?"

Levi shook his head. "Only the lowest level and the second floor above ground are separated. the upper water floor and lowest land floor meet, it's half half so we actually share the same home. You'll see when it's finished, shitty glasses."

"Oh, I see! So basically the ground is just water and bridges! I can't wait to see it when it's done, when do you think you guys will finish?"

Eren leaned closer to Hanji with a happy smile and held up a hand, showing them four fingers. "Four, house. Three, home!"

Hanji clapped their hands together excitedly. "Can I help decorate?? Pretty please?"

"Yes!" Eren agreed before Levi could object.

"Yay!" Hanji cheered. "So, are you guys staying here tonight?"

Levi shrugged in response. "Yeah, but I'll drop by in the morning for a shower and food."

Happily, Hanji made their leave with a wave and left the couple alone.

"Eren, let's just sleep, I'm exhausted as hell..."

The mermaid giggled. "Yes. I love you, Levi."

"Love you too, brat."


	20. Forever Yours

"Truly amazing."

Levi got startled and turned around, glaring at the blonde man. "For fuck's sake, Erwin, don't sneak up on me like that!"

Erwin only smiled at that. "I heard from Dr. Zoe that your house is almost done, so I came by to see it myself. Care for a quick tour?"

"Sure, why not. Just wait a second." Levi said and then ran over to Eren, who held the pump to fill out the roof with concrete. "Hey, Eren! Eyebrows want a tour!"

The mermaid nodded and finished the filling before turning into his smaller form and swam inside.

"Alright, come on in."

They entered through the doorway, and Erwin froze in amazement. The white floor seemed to float above the water, with a good half only covering it. Eren broke the surface and waved excitedly.

"Brēwō!"

"Good morning, Eren." Erwin smiled and looked around more.

"The space over the will be the kitchen, with a shallow part for Eren to eat with me at the low table that'll arrive tomorrow. Then, over there is already installed the TV, we will move the couch in later today and the water passage next to it is also shallow enough for Eren to chill with us. The toilet and shower are behind the door to your right. Next up, there in the corner are the stairs leading up to the study and private bathroom and the other door next to it leads to our shared bedroom." Levi explained.

"You share a bedroom?" Erwin asked curiously.

Levi nodded and smirked a bit with pride. "Yeah, Eren sleeps dry, covered with flesh from his deep sea form."

Erwin nodded in awe. "Incredible... and what's with the door over there?"

"Pool!" Eren answered with a grin, then pointed down at the water below him. "Swim?"

"Of course, I want to see the whole house, but I'll go to the second floor first, okay? Wouldn't want to make Levi's floors wet."

Eren nodded and swam to the kitchen, sitting down at the shallow part that was more or less his chair.

After a few minutes, they returned and Erwin changed into swim shorts he brought with him before joining Eren in the shallow parts.

"Alright, lead the way." he said smiling and slipped down, letting himself be guided by Eren underneath the floor.

The mermaid showed him his own underwater couch slash chill area, then after a breath taking pause swam with the tall man through the small hole to the lowest level with ocean floor and walls already decorated with the most beautiful shells and a plastic coral reef in bright colors. He quickly showed Erwin his entrance to his part of the house before going up again and swimming underneath a doorway, then dragged himself into the bedroom.

The floor there wasn't even, instead lowered in the middle and filled out with soft blankets and pillows.

And just before the dent was a small shelf with towels. Erwin got himself one to dry off and then returned to the main floor through the door, while Eren swam underneath it and surfaced in the kitchen.

"And?" Levi asked proudly.

"It's quite impressive. The combination between floor and water is amazing, did you design this yourself?"

Levi shook his head, sighing heavily. "Shitty glasses helped with the design and the finishing touch to make it all stable did an actual architect. But the main idea was mine."

Erwin hummed. "Still. It's just amazing, really good."

Eren smiled at the impressed man. "I know. Pretty home for my pretty Levi!"

Levi stared at his mermaid, his face steadily growing red. "Don't say shit like that, you idiot..."

"I think I'll leave you to yourselves. Take care." Erwin chuckled, waving at them before he left.

The second he was gone, Levi turned to Eren with a glare. "You. Me. Bedroom. Now."

The mermaid raised his eyes brows, then smirked in a seductive way and slipped underwater. Levi rushed to the bedroom as well, opening the door to see Eren already rolling around in towels before getting into their bed that was more like a nest. Levi quickly got rid of his clothes before joining his mate.

"Mate." Eren purred into Levi's ear, making the raven shiver. "Levi, I want mate you."

Levi nodded, pulling Eren closer against him and rubbing their hips together. His eyes widened when Eren slid down his body to take his member into his hand and licked along the length.

"Hah, ah, Eren..."

The mermaid licked a bit more, then gently sucked the tip, drawing a moan from Levi. He smiled when he could feel the other man fully harden.

"Feel good?"

Levi gasped at the soft vibration of Eren's voice and nodded again.

"Good." Eren chuckled, filled with lust and stopped a second as Levi wet the fingers of one hand, then gently pushed him away before nearing his limit and began rubbing Eren's entrance. When he felt Eren bucking his hips on instinct, he carefully put a finger inside.

"Levi! Yes, mate. Mate, mate, mate..." Eren chanted as Levi worked his finger inside him.

"I'll mate you so fucking hard you won't remember your name..." Levi said in a low, lustful tone and added his other spit-coated fingers easily, Eren's body spreading like he was made for this.

"L-Levi!" Eren cried out when apparently the human hit his sweet spot.

"Fuck, Eren, I can't hold back longer..." the older male cursed, stroking his member while looking his mate in the eyes before slowly pushing inside.

Eren gasped and smiled at Levi when he had bottomed out. "Levi, tarhjan mī! Ik weljan ī þīna!"  
 _(Levi, mark me! I want to be yours forever!)_

"You're too cute," Levi whispered and nipped at Eren's neck as he started to thrust. The mermaid moaned and flipped his tail to move his hips up and down in rhythm of Levi's thrusts.

Levi gently reached for Eren's member and stroked it with the hand that wasn't curled around the tail. The mermaid moaned, his entrance twitching at the feeling and they began moving faster and harder, without any hesitation.

They both moaned loudly and Levi lost himself in the sensation.

"L-Levi... I-I...!" Eren gasped for air soon after and clung to Levi, reaching his limit.

"Come with me Eren!" Levi moaned and a few moments after felt Eren tighten around him as he came all over his chest.

The raven followed a few thrusts after, cumming deep inside. They stayed like that for a minute, just catching their breath, until Levi pulled out and pressed Eren against him.

"This... good..." Eren panted with a smirk.

Levi nodded in return. "Yeah... definitely the best sex I've ever had..."

Eren smiled and tilted his head to show Levi his neck. "Tarhjan me, Levi!"

When Levi just looked confused, he whined in desperation. "Levi... eat..."

"I won't fucking eat you, Eren," Levi grumbled but bit down hard enough on Eren's shoulder to draw a bit of blood.

Eren hummed in content and tilted his head back once Levi let go to do the same to his mate. Levi gasped when the teeth pierced his flesh, clutching Eren closer.

When they finally parted, Eren's eyes seemed to glaze over before he laid down against Levi, his flesh cocoon building up around them.

"A nap sounds good..." Levi mused and hugged Eren as they fell asleep together.

**Notes for the Chapter:**

> We are slowly reaching the end my dudes, this story will be finished on thursday with the next and last chapter
> 
> *Sound of Silence playing in the distance*


	21. from House to Home

**Notes for the Chapter:**

> This chapter are small, cute pieces of how their house became their home. Enjoy! :D

When Levi woke up about an hour later, he let go of Eren to notice him smelling a bit odd. The mermaid smelled different, but in a good way. The smell of the sea had disappeared almost completely and the sensation of just Eren intensified in an addictive way.

_'Fuck he smells amazing...'_

Levi shook the thought out of his head to gently wake up his mate to let him out. With a small whine, Eren complied but closed the cocoon right after Levi was out.

"Was it that exhausting for him...?" Levi wondered before showering and then getting back to work with the house. With the help of Hanji, he managed it to put most of the furniture inside and by the end of the day, the workers had also finished the roof.

Hanji left after getting them dinner, and Levi took his and Eren's plate to the bedroom.

"Hey, Eren. Wake up, dinner's ready."

A muffled yawn echoed inside the flesh before it dissolved to reveal an Eren with ruffled hair and small bruises in all the right places, as well as swollen lips.

"Hanji got you tuna, hope you like it," Levi said as he sat down next to the mermaid, who reached for the plate greedily.

"Yes, thanks, Levi!" Eren smiled and then ripped the poor fish apart with his teeth, swallowing the bits whole.

Levi rolled his eyes at the non-existent manners of his mate and then started to eat his own plate. After they had finished, Levi motioned for Eren to come closer and buried his nose in the mermaid's hair.

"Just what is that smell? It's so good..."

Eren pulled away to look at Levi with wide eyes. "Levi like I smell? I no know human like smell..."

"What do you mean?" Levi asked, reaching over to the nightstand to give Eren the dictionary.

Eren flipped several minutes through the pages before he spoke up again. "Mated mermaid smells different. Normal, other no like smell, only mermaid mate. I no know human do that."

"We don't... but I still somehow like your smell... it's weird."

Eren grinned like a child on Christmas morning. "I happy you like smell!" he said and wrapped his tail around Levi, then pulled him into a passionate kiss.

-~-

After a rather peaceful night, the couple woke up the next morning with Hanji banging loudly against the door.

"That shitty glasses..." Levi sighed. "Couldn't your cocoon be more sound proof?"

Eren blinked at Levi confused, his eyes and tail starting to glow brightly enough that they could see each other completely.

"Hanji?"

The human nodded and slowly got up, Eren dissolving the flesh to let them out. The couple got to the front door and Levi opened the door to reveal an overly excited Hanji in a boiler suit.

"Where the fuck did you even get that?"

"Morning to you too Levi, we still have to paint the walls and ceiling! And I just saw the truck arrive with the kitchen!" they said and pointed at the boxes next to them.

The man groaned, holding his head. "Don't tell me you send the guys away."

Hanji giggled. "But I did! Don't worry, there are instructions on how to build it and I'm sure we will have fun today!"

Eren pouted from his spot, not understanding a thing. "Hanji, I want hello."

The scientist made a fake gasp and ran over to pet Eren's head. "Sorry, sorry. Good morning, Eren!" they stopped for a second and then got closer to the brunette. "What did mean Levi do to you?"

"What do you mean, shitty glasses?" Levi asked since he was one of the two of them without healing powers and was still stuck with the mating wounds.

"He smells like you decided to clean him with butyric acid!" Hanji huffed.

Levi blinked a few times in confusion before it hit him, causing him to smirk together with his mate. "So it actually works... weird. And amazing. But mostly weird as shit."

"What?"

Eren's smirk widened. "Mate like I smell. No mate no like I smell."

Hanji clapped their hands together, face lighting up. "Whaaaaat!? How cool! So your body gives off a different smell after mating! It's really weird that Levi likes your pheromones, normally it only works between the same species, and how come only the mate likes it-"

"Oh my god, Hanji shut the hell up." Levi sighed. "Let's just build that shitty kitchen."

"Yes, sir!" Hanji laughed. "How about breakfast first?"

Half an hour later, Levi returned with breakfast from a nearby bakery to see Hanji setting up the kitchen parts in the right spot while Eren worked with the electric screwdriver.

"Are you guys fucking serious? Eren. Water. And electricity?!"

Hanji laughed and took the bags from Levi. "Oh don't make such a fuss, Eren's being care-"

Right in that moment, Eren slipped and the screwdriver fell into the shallow water. The mermaid twitched, and after the scientist shoved the bags back at Levi and carefully retrieved the machine out of the water, burnt out and smoking a little, Hanji began laughing.

"Oh my- I'm so sorry Eren! But the moment... just so cliché!"

Eren joined, chuckling quietly. "I fine. Aba feel weird!"

Levi sighed in relief, set the bags down and walked over to punch Hanji on the head. "You can be so happy a screwdriver doesn't have much juice, if it had shocked Eren hard I would've killed you."

Hanji's laughing slowly died down. "No harm was done, Levi. Except that now we have to screw now with our hands. But of course, I checked if it could actually hurt Eren!"

"You just want to do your weird experiments..." Levi grumbled but opened the bags with sandwiches. "Eren, I got you one with tuna. Can you eat bread or do you just want the fish?"

Eren's eyes lit up and he reached for the sandwich. "Brauda!"

"You're cuter than what should be legal," Levi said as he gave Eren the bread. They ate their sandwiches with Eren making happy sounds while eating.

Afterward, they all build the kitchen and the table together and then painted the walls. The kitchen in a sand tone, the living room in soft, almost white turquoise and the rest light ocean blue, the ceiling white.

Hanji took off the suit to show them in swimming clothes before they jumped into the water. "The water's great! Now, Eren. Tell me all about y-"

Eren looked at Levi for approval before fleeing outside the house into the depths of the ocean.

"Serves you right, shitty glasses." Levi smirked.

Hanji waited for a good hour before they realized Eren wouldn't come back soon. With a heavy sigh, they left eventually, leaving the raven behind to make the first dinner in his new kitchen.

Levi made the meal around eight and ate alone 30 minutes later when it was mostly cold. He later opened a bottle of wine and walked out onto the veranda, to look out to the ocean, silently waiting for his mate to return.

-~-

"Levi!"

He was woken up sometime later, shot up in his seat. The human put the empty glass aside he had hugged in his sleep and looked down at a smiling Eren.

"Fucking finally. Where have you been?" Levi asked with a frown.

"I have Skatta!" Eren answered, his eyes and tail beginning to glow softly.

"Skatta?" Levi asked and made Eren wait for a moment to get his dictionary and looked it up. "Oh, you went treasure hunting? Have you found anything interesting?"

Eren nodded and ducked underwater before dumping everything on the veranda. Levi's eyes widened and he felt his heart tighten at the thought of how he could tell Eren the truth about his treasure.

"Eren..." he sighed and got a bit closer. In a pile was one-half of an old tire, several batteries and cans, along with tons of colorful little pieces of plastic.

"What?"

"Eren... uhm... this isn't a treasure... no skatta." Levi looked at his mate with sympathy. "This is trash. People throw away things into the ocean sometimes..."

To prove his point, Levi showed Eren his own cans and batteries he had in the house. "And the plastic like the labels on this," he pointed at the label of a plastic bottle, "ends up as this." he points at the small pieces.

The mermaid frowned, and Levi was surprised when instead of the sad, disappointed face he expected, pure rage filled the brunette's features. "Levi, that eat bad?"

Levi nodded. "It can kill various kinds of ocean creatures. Why?"

Eren glared at the pile before throwing it outraged back into the ocean. "I big, I eat that. I want eat fish... aba that everywhere! I think skatta... Aba you human kill water!"

"Yeah... Many people are idiots who don't care about the ocean... Maybe we could at least clean the area around here? I want to keep this house clean, so your part should be clean as well."

"Blauþu homo..." Eren angrily growled but his look softened a little as he dropped his head. "Once we clean house, then this no house, Levi."

"What else, then?"

"Then it haima. It home, Levi."

Levi hummed. "From house to home..."

**Notes for the Chapter:**

> Hope you liked this my dudes, I'm already working on another Ereri fic and I hope that will turn out as great as this did and yeah... I love you all that's what I want to say here <3

**Author's Note:**

> If you like it, leave a nice comment and kudos, it makes a writer's day! ♥


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